The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
This is neither tested nor compiled. I was working on Samsung's Arndale board and so was required to samsung serial driver. Then thought why not others :)
Rebased over: v3.11-rc5
Cc: Bryan Huntsman bryanh@codeaurora.org Cc: Daniel Walker dwalker@fifo99.com Cc: David Brown davidb@codeaurora.org Cc: Stephen Warren swarren@wwwdotorg.org Cc: Tobias Klauser tklauser@distanz.ch Cc: Tony Prisk linux@prisktech.co.nz
Viresh Kumar (25): tty: serial: altera_jtag: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: altera: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: apbuart: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: ar933x: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: arc: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: bcm63xx: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: bfin_sport: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: efm32: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: icom: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: lpc32xx_hs: don't call tty_flip_buffer_push() twice tty: serial: lpc32xx_hs: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: m32r_sio: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: mcf: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: mfd: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: mpsc: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: msm: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: netx: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: nwpserial: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: pnx8xxx: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: rp2: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: sa1100: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: samsung: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: sirfsoc: drop uart_port->lock before calling tty_flip_buffer_push() tty: serial: vt8500: drop uart_port->lock before calling tty_flip_buffer_push()
drivers/tty/serial/altera_jtaguart.c | 2 ++ drivers/tty/serial/altera_uart.c | 2 ++ drivers/tty/serial/apbuart.c | 2 ++ drivers/tty/serial/ar933x_uart.c | 2 ++ drivers/tty/serial/arc_uart.c | 2 ++ drivers/tty/serial/bcm63xx_uart.c | 2 ++ drivers/tty/serial/bfin_sport_uart.c | 5 +++-- drivers/tty/serial/efm32-uart.c | 4 ++-- drivers/tty/serial/icom.c | 3 +++ drivers/tty/serial/lpc32xx_hs.c | 7 ++++--- drivers/tty/serial/m32r_sio.c | 3 +++ drivers/tty/serial/mcf.c | 2 ++ drivers/tty/serial/mfd.c | 14 ++++++++++---- drivers/tty/serial/mpsc.c | 11 ++++++++--- drivers/tty/serial/msm_serial.c | 5 +++++ drivers/tty/serial/netx-serial.c | 6 ++++-- drivers/tty/serial/nwpserial.c | 3 +++ drivers/tty/serial/pnx8xxx_uart.c | 3 +++ drivers/tty/serial/rp2.c | 2 ++ drivers/tty/serial/sa1100.c | 3 +++ drivers/tty/serial/samsung.c | 5 ++++- drivers/tty/serial/serial-tegra.c | 10 ++++++++-- drivers/tty/serial/sirfsoc_uart.c | 3 +++ drivers/tty/serial/vt8500_serial.c | 2 ++ 24 files changed, 84 insertions(+), 19 deletions(-)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Cc: Tobias Klauser tklauser@distanz.ch Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/altera_jtaguart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c index c6bdb94..46c25ff 100644 --- a/drivers/tty/serial/altera_jtaguart.c +++ b/drivers/tty/serial/altera_jtaguart.c @@ -139,7 +139,9 @@ static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp) uart_insert_char(port, 0, 0, ch, flag); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); }
static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Cc: Tobias Klauser tklauser@distanz.ch Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/altera_uart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c index 1d46966..77641e7 100644 --- a/drivers/tty/serial/altera_uart.c +++ b/drivers/tty/serial/altera_uart.c @@ -231,7 +231,9 @@ static void altera_uart_rx_chars(struct altera_uart *pp) flag); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); }
static void altera_uart_tx_chars(struct altera_uart *pp)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/apbuart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c index 6331464d..de11ab8 100644 --- a/drivers/tty/serial/apbuart.c +++ b/drivers/tty/serial/apbuart.c @@ -125,7 +125,9 @@ static void apbuart_rx_chars(struct uart_port *port) status = UART_GET_STATUS(port); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); }
static void apbuart_tx_chars(struct uart_port *port)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/ar933x_uart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c index 27f20c5..964ca90 100644 --- a/drivers/tty/serial/ar933x_uart.c +++ b/drivers/tty/serial/ar933x_uart.c @@ -322,7 +322,9 @@ static void ar933x_uart_rx_chars(struct ar933x_uart_port *up) tty_insert_flip_char(port, ch, TTY_NORMAL); } while (max_count-- > 0);
+ spin_unlock(&up->port.lock); tty_flip_buffer_push(port); + spin_lock(&up->port.lock); }
static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/arc_uart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c index 22f280a..8cf6b30 100644 --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -248,7 +248,9 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart) uart_insert_char(&uart->port, status, RXOERR, ch, flg);
done: + spin_unlock(&uart->port.lock); tty_flip_buffer_push(&uart->port.state->port); + spin_lock(&uart->port.lock); } }
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/bcm63xx_uart.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c index 6fa2ae77..9f0bf4c 100644 --- a/drivers/tty/serial/bcm63xx_uart.c +++ b/drivers/tty/serial/bcm63xx_uart.c @@ -302,7 +302,9 @@ static void bcm_uart_do_rx(struct uart_port *port)
} while (--max_count);
+ spin_unlock(&port->lock); tty_flip_buffer_push(tty_port); + spin_lock(&port->lock); }
/*
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/bfin_sport_uart.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/bfin_sport_uart.c b/drivers/tty/serial/bfin_sport_uart.c index 487c173..32d3926 100644 --- a/drivers/tty/serial/bfin_sport_uart.c +++ b/drivers/tty/serial/bfin_sport_uart.c @@ -161,11 +161,12 @@ static irqreturn_t sport_uart_rx_irq(int irq, void *dev_id) if (!uart_handle_sysrq_char(&up->port, ch)) tty_insert_flip_char(port, ch, TTY_NORMAL); } - /* XXX this won't deadlock with lowlat? */ - tty_flip_buffer_push(port);
spin_unlock(&up->port.lock);
+ /* XXX this won't deadlock with lowlat? */ + tty_flip_buffer_push(port); + return IRQ_HANDLED; }
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/efm32-uart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/efm32-uart.c b/drivers/tty/serial/efm32-uart.c index 7d199c8..b4cef79 100644 --- a/drivers/tty/serial/efm32-uart.c +++ b/drivers/tty/serial/efm32-uart.c @@ -268,10 +268,10 @@ static irqreturn_t efm32_uart_rxirq(int irq, void *data) handled = IRQ_HANDLED; }
- tty_flip_buffer_push(tport); - spin_unlock(&port->lock);
+ tty_flip_buffer_push(tport); + return handled; }
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/icom.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c index 18ed5ae..46cb597 100644 --- a/drivers/tty/serial/icom.c +++ b/drivers/tty/serial/icom.c @@ -834,7 +834,10 @@ ignore_char: status = cpu_to_le16(icom_port->statStg->rcv[rcv_buff].flags); } icom_port->next_rcv = rcv_buff; + + spin_unlock(&icom_port->uart_port.lock); tty_flip_buffer_push(port); + spin_lock(&icom_port->uart_port.lock); }
static void process_interrupt(u16 port_int_reg,
serial_lpc32xx_interrupt() calls __serial_lpc32xx_rx() first and then tty_flip_buffer_push() immediately after that. But last statement of __serial_lpc32xx_rx() already called tty_flip_buffer_push()..
So, probably its not required to be called twice. Lets remove one of them.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/lpc32xx_hs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c index dffea6b..8fdf6a8 100644 --- a/drivers/tty/serial/lpc32xx_hs.c +++ b/drivers/tty/serial/lpc32xx_hs.c @@ -351,10 +351,8 @@ static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id) }
/* Data received? */ - if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT)) { + if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT)) __serial_lpc32xx_rx(port); - tty_flip_buffer_push(tport); - }
/* Transmit data request? */ if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/lpc32xx_hs.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c index 8fdf6a8..701644f 100644 --- a/drivers/tty/serial/lpc32xx_hs.c +++ b/drivers/tty/serial/lpc32xx_hs.c @@ -279,7 +279,10 @@ static void __serial_lpc32xx_rx(struct uart_port *port)
tmp = readl(LPC32XX_HSUART_FIFO(port->membase)); } + + spin_unlock(&port->lock); tty_flip_buffer_push(tport); + spin_lock(&port->lock); }
static void __serial_lpc32xx_tx(struct uart_port *port)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/m32r_sio.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/m32r_sio.c b/drivers/tty/serial/m32r_sio.c index bb1afa0..9cd9b4e 100644 --- a/drivers/tty/serial/m32r_sio.c +++ b/drivers/tty/serial/m32r_sio.c @@ -368,7 +368,10 @@ static void receive_chars(struct uart_sio_port *up, int *status) ignore_char: *status = serial_in(up, UART_LSR); } while ((*status & UART_LSR_DR) && (max_count-- > 0)); + + spin_unlock(&up->port.lock); tty_flip_buffer_push(port); + spin_lock(&up->port.lock); }
static void transmit_chars(struct uart_sio_port *up)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/mcf.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c index 65be0c0..62c8fdf 100644 --- a/drivers/tty/serial/mcf.c +++ b/drivers/tty/serial/mcf.c @@ -324,7 +324,9 @@ static void mcf_rx_chars(struct mcf_uart *pp) uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); }
/****************************************************************************/
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/mfd.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c index 4a82267..d3db042 100644 --- a/drivers/tty/serial/mfd.c +++ b/drivers/tty/serial/mfd.c @@ -386,7 +386,7 @@ static void serial_hsu_stop_tx(struct uart_port *port)
/* This is always called in spinlock protected mode, so * modify timeout timer is safe here */ -void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts) +void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts, unsigned long *flags) { struct hsu_dma_buffer *dbuf = &up->rxbuf; struct hsu_dma_chan *chan = up->rxc; @@ -438,7 +438,9 @@ void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts) | (0x1 << 16) | (0x1 << 24) /* timeout bit, see HSU Errata 1 */ ); + spin_unlock_irqrestore(&up->port.lock, *flags); tty_flip_buffer_push(tport); + spin_lock_irqsave(&up->port.lock, *flags);
chan_writel(chan, HSU_CH_CR, 0x3);
@@ -459,7 +461,8 @@ static void serial_hsu_stop_rx(struct uart_port *port) } }
-static inline void receive_chars(struct uart_hsu_port *up, int *status) +static inline void receive_chars(struct uart_hsu_port *up, int *status, + unsigned long *flags) { unsigned int ch, flag; unsigned int max_count = 256; @@ -519,7 +522,10 @@ static inline void receive_chars(struct uart_hsu_port *up, int *status) ignore_char: *status = serial_in(up, UART_LSR); } while ((*status & UART_LSR_DR) && max_count--); + + spin_unlock_irqrestore(&up->port.lock, *flags); tty_flip_buffer_push(&up->port.state->port); + spin_lock_irqsave(&up->port.lock, *flags); }
static void transmit_chars(struct uart_hsu_port *up) @@ -613,7 +619,7 @@ static irqreturn_t port_irq(int irq, void *dev_id)
lsr = serial_in(up, UART_LSR); if (lsr & UART_LSR_DR) - receive_chars(up, &lsr); + receive_chars(up, &lsr, &flags); check_modem_status(up);
/* lsr will be renewed during the receive_chars */ @@ -643,7 +649,7 @@ static inline void dma_chan_irq(struct hsu_dma_chan *chan)
/* Rx channel */ if (chan->dirt == DMA_FROM_DEVICE) - hsu_dma_rx(up, int_sts); + hsu_dma_rx(up, int_sts, &flags);
/* Tx channel */ if (chan->dirt == DMA_TO_DEVICE) {
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/mpsc.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/mpsc.c b/drivers/tty/serial/mpsc.c index bc24f49..556ff04 100644 --- a/drivers/tty/serial/mpsc.c +++ b/drivers/tty/serial/mpsc.c @@ -934,7 +934,7 @@ static int serial_polled; ****************************************************************************** */
-static int mpsc_rx_intr(struct mpsc_port_info *pi) +static int mpsc_rx_intr(struct mpsc_port_info *pi, unsigned long *flags) { struct mpsc_rx_desc *rxre; struct tty_port *port = &pi->port.state->port; @@ -969,8 +969,11 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi) #endif /* Following use of tty struct directly is deprecated */ if (tty_buffer_request_room(port, bytes_in) < bytes_in) { - if (port->low_latency) + if (port->low_latency) { + spin_unlock_irqrestore(&pi->port.lock, *flags); tty_flip_buffer_push(port); + spin_lock_irqsave(&pi->port.lock, *flags); + } /* * If this failed then we will throw away the bytes * but must do so to clear interrupts. @@ -1080,7 +1083,9 @@ next_frame: if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0) mpsc_start_rx(pi);
+ spin_unlock_irqrestore(&pi->port.lock, *flags); tty_flip_buffer_push(port); + spin_lock_irqsave(&pi->port.lock, *flags); return rc; }
@@ -1222,7 +1227,7 @@ static irqreturn_t mpsc_sdma_intr(int irq, void *dev_id)
spin_lock_irqsave(&pi->port.lock, iflags); mpsc_sdma_intr_ack(pi); - if (mpsc_rx_intr(pi)) + if (mpsc_rx_intr(pi, &iflags)) rc = IRQ_HANDLED; if (mpsc_tx_intr(pi)) rc = IRQ_HANDLED;
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Cc: David Brown davidb@codeaurora.org (maintainer:ARM/QUALCOMM MSM...) Cc: Daniel Walker dwalker@fifo99.com (maintainer:ARM/QUALCOMM MSM...) Cc: Bryan Huntsman bryanh@codeaurora.org (maintainer:ARM/QUALCOMM MSM...) Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/msm_serial.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 2c6cfb3..daa2837 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -137,7 +137,10 @@ static void handle_rx_dm(struct uart_port *port, unsigned int misr) count -= 4; }
+ spin_unlock(&port->lock); tty_flip_buffer_push(tport); + spin_lock(&port->lock); + if (misr & (UART_IMR_RXSTALE)) msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); msm_write(port, 0xFFFFFF, UARTDM_DMRX); @@ -189,7 +192,9 @@ static void handle_rx(struct uart_port *port) tty_insert_flip_char(tport, c, flag); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(tport); + spin_lock(&port->lock); }
static void reset_dm_count(struct uart_port *port)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/netx-serial.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/netx-serial.c b/drivers/tty/serial/netx-serial.c index b9a40ed..4f59c4d 100644 --- a/drivers/tty/serial/netx-serial.c +++ b/drivers/tty/serial/netx-serial.c @@ -196,7 +196,7 @@ static void netx_txint(struct uart_port *port) uart_write_wakeup(port); }
-static void netx_rxint(struct uart_port *port) +static void netx_rxint(struct uart_port *port, unsigned long *flags) { unsigned char rx, flg, status;
@@ -236,7 +236,9 @@ static void netx_rxint(struct uart_port *port) uart_insert_char(port, status, SR_OE, rx, flg); }
+ spin_unlock_irqrestore(&port->lock, *flags); tty_flip_buffer_push(&port->state->port); + spin_lock_irqsave(&port->lock, *flags); }
static irqreturn_t netx_int(int irq, void *dev_id) @@ -250,7 +252,7 @@ static irqreturn_t netx_int(int irq, void *dev_id) status = readl(port->membase + UART_IIR) & IIR_MASK; while (status) { if (status & IIR_RIS) - netx_rxint(port); + netx_rxint(port, &flags); if (status & IIR_TIS) netx_txint(port); if (status & IIR_MIS) {
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/nwpserial.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/nwpserial.c b/drivers/tty/serial/nwpserial.c index 549c70a..693bc6c 100644 --- a/drivers/tty/serial/nwpserial.c +++ b/drivers/tty/serial/nwpserial.c @@ -149,7 +149,10 @@ static irqreturn_t nwpserial_interrupt(int irq, void *dev_id) tty_insert_flip_char(port, ch, TTY_NORMAL); } while (dcr_read(up->dcr_host, UART_LSR) & UART_LSR_DR);
+ spin_unlock(&up->port.lock); tty_flip_buffer_push(port); + spin_lock(&up->port.lock); + ret = IRQ_HANDLED;
/* clear interrupt */
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/pnx8xxx_uart.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/pnx8xxx_uart.c b/drivers/tty/serial/pnx8xxx_uart.c index 7e277a5..8db7482 100644 --- a/drivers/tty/serial/pnx8xxx_uart.c +++ b/drivers/tty/serial/pnx8xxx_uart.c @@ -237,7 +237,10 @@ static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport) status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) | ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT)); } + + spin_unlock(&sport->port.lock); tty_flip_buffer_push(&sport->port.state->port); + spin_lock(&sport->port.lock); }
static void pnx8xxx_tx_chars(struct pnx8xxx_port *sport)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/rp2.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/rp2.c b/drivers/tty/serial/rp2.c index a314a94..328d6de 100644 --- a/drivers/tty/serial/rp2.c +++ b/drivers/tty/serial/rp2.c @@ -427,7 +427,9 @@ static void rp2_rx_chars(struct rp2_uart_port *up) up->port.icount.rx++; }
+ spin_unlock(&up->port.lock); tty_flip_buffer_push(port); + spin_lock(&up->port.lock); }
static void rp2_tx_chars(struct rp2_uart_port *up)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/sa1100.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c index af6b3e3..28d60ef 100644 --- a/drivers/tty/serial/sa1100.c +++ b/drivers/tty/serial/sa1100.c @@ -232,7 +232,10 @@ sa1100_rx_chars(struct sa1100_port *sport) status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) | UTSR0_TO_SM(UART_GET_UTSR0(sport)); } + + spin_unlock(&sport->port.lock); tty_flip_buffer_push(&sport->port.state->port); + spin_lock(&sport->port.lock); }
static void sa1100_tx_chars(struct sa1100_port *sport)
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/samsung.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index 376079b..275e3e0 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -249,6 +249,8 @@ s3c24xx_serial_rx_chars(int irq, void *dev_id) ufcon |= S3C2410_UFCON_RESETRX; wr_regl(port, S3C2410_UFCON, ufcon); rx_enabled(port) = 1; + spin_unlock_irqrestore(&port->lock, + flags); goto out; } continue; @@ -297,10 +299,11 @@ s3c24xx_serial_rx_chars(int irq, void *dev_id) ignore_char: continue; } + + spin_unlock_irqrestore(&port->lock, flags); tty_flip_buffer_push(&port->state->port);
out: - spin_unlock_irqrestore(&port->lock, flags); return IRQ_HANDLED; }
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Cc: Stephen Warren swarren@wwwdotorg.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/serial-tegra.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index ee7c812..82846cf 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -571,7 +571,9 @@ static void tegra_uart_rx_dma_complete(void *args)
tegra_uart_handle_rx_pio(tup, port); if (tty) { + spin_unlock_irqrestore(&u->lock, flags); tty_flip_buffer_push(port); + spin_lock_irqsave(&u->lock, flags); tty_kref_put(tty); } tegra_uart_start_rx_dma(tup); @@ -583,11 +585,13 @@ static void tegra_uart_rx_dma_complete(void *args) spin_unlock_irqrestore(&u->lock, flags); }
-static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup) +static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup, + unsigned long *flags) { struct dma_tx_state state; struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port); struct tty_port *port = &tup->uport.state->port; + struct uart_port *u = &tup->uport; int count;
/* Deactivate flow control to stop sender */ @@ -604,7 +608,9 @@ static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
tegra_uart_handle_rx_pio(tup, port); if (tty) { + spin_unlock_irqrestore(&u->lock, *flags); tty_flip_buffer_push(port); + spin_lock_irqsave(&u->lock, *flags); tty_kref_put(tty); } tegra_uart_start_rx_dma(tup); @@ -671,7 +677,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) iir = tegra_uart_read(tup, UART_IIR); if (iir & UART_IIR_NO_INT) { if (is_rx_int) { - tegra_uart_handle_rx_dma(tup); + tegra_uart_handle_rx_dma(tup, &flags); if (tup->rx_in_progress) { ier = tup->ier_shadow; ier |= (UART_IER_RLSI | UART_IER_RTOIE |
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/sirfsoc_uart.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c index 1fd564b..bc289fe 100644 --- a/drivers/tty/serial/sirfsoc_uart.c +++ b/drivers/tty/serial/sirfsoc_uart.c @@ -219,7 +219,10 @@ sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count) }
port->icount.rx += rx_count; + + spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock);
return rx_count; }
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers locking
Cc: Tony Prisk linux@prisktech.co.nz Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/tty/serial/vt8500_serial.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c index 48af43d..b839b98 100644 --- a/drivers/tty/serial/vt8500_serial.c +++ b/drivers/tty/serial/vt8500_serial.c @@ -170,7 +170,9 @@ static void handle_rx(struct uart_port *port) tty_insert_flip_char(tport, c, flag); }
+ spin_unlock(&port->lock); tty_flip_buffer_push(tport); + spin_lock(&port->lock); }
static void handle_tx(struct uart_port *port)
On 08/16/2013 07:43 AM, Viresh Kumar wrote:
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
Please include the lockdep warning in the changelog.
Does this happen on linux-next?
Regards, Peter Hurley
On 16 August 2013 17:36, Peter Hurley peter@hurleysoftware.com wrote:
Please include the lockdep warning in the changelog.
Sure.. For now it is here, will include it in V2..
====================================================== [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] 3.10.6-linaro-arndale #1 Not tainted ------------------------------------------------------ swapper/0/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: (&(&(&bank->slock)->lock)->wait_lock){+.+...}, at: [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8
and this task is already holding: (&irq_desc_lock_class){-.....}, at: [<800bbe18>] __setup_irq+0x94/0x4c4 which would create a new lock dependency: (&irq_desc_lock_class){-.....} -> (&(&(&bank->slock)->lock)->wait_lock){+.+...}
but this new dependency connects a HARDIRQ-irq-safe lock: (&irq_desc_lock_class){-.....} ... which became HARDIRQ-irq-safe at: [<8008ffa0>] mark_lock+0x180/0x808 [<80092a38>] __lock_acquire+0xb5c/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<800bdb10>] handle_fasteoi_irq+0x24/0x15c [<800b9c8c>] generic_handle_irq+0x34/0x44 [<8002007c>] handle_IRQ+0x50/0xa0 [<800085d8>] gic_handle_irq+0x48/0x78 [<8001f1c4>] __irq_svc+0x44/0x8c [<800204a4>] arch_cpu_idle+0x40/0x4c [<800815f8>] cpu_startup_entry+0x1a4/0x2dc [<8067b780>] rest_init+0xdc/0xec [<80910c34>] start_kernel+0x428/0x434 [<40008084>] 0x40008084
to a HARDIRQ-irq-unsafe lock: (&(&(&bank->slock)->lock)->wait_lock){+.+...} ... which became HARDIRQ-irq-unsafe at: ... [<8008ffa0>] mark_lock+0x180/0x808 [<80092498>] __lock_acquire+0x5bc/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d0594>] samsung_pinconf_rw+0xc8/0x14c [<803d06dc>] samsung_pinconf_group_set+0x70/0x90 [<803cf864>] pinconf_apply_setting+0x90/0x198 [<803cc07c>] pinctrl_select_state+0xf0/0x1a8 [<80436790>] pinctrl_bind_pins+0x7c/0xd4 [<8041c900>] driver_probe_device+0x68/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<809426e0>] i2c_adap_s3c_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(&(&(&bank->slock)->lock)->wait_lock); local_irq_disable(); lock(&irq_desc_lock_class); lock(&(&(&bank->slock)->lock)->wait_lock); <Interrupt> lock(&irq_desc_lock_class);
*** DEADLOCK ***
2 locks held by swapper/0/1: #0: (&__lockdep_no_validate__){......}, at: [<8041cb7c>] __driver_attach+0x60/0xa0 #1: (&irq_desc_lock_class){-.....}, at: [<800bbe18>] __setup_irq+0x94/0x4c4
the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&irq_desc_lock_class){-.....} ops: 3893 { IN-HARDIRQ-W at: [<8008ffa0>] mark_lock+0x180/0x808 [<80092a38>] __lock_acquire+0xb5c/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<800bdb10>] handle_fasteoi_irq+0x24/0x15c [<800b9c8c>] generic_handle_irq+0x34/0x44 [<8002007c>] handle_IRQ+0x50/0xa0 [<800085d8>] gic_handle_irq+0x48/0x78 [<8001f1c4>] __irq_svc+0x44/0x8c [<800204a4>] arch_cpu_idle+0x40/0x4c [<800815f8>] cpu_startup_entry+0x1a4/0x2dc [<8067b780>] rest_init+0xdc/0xec [<80910c34>] start_kernel+0x428/0x434 [<40008084>] 0x40008084 INITIAL USE at: [<8008ffa0>] mark_lock+0x180/0x808 [<8009219c>] __lock_acquire+0x2c0/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cd88>] _raw_spin_lock_irqsave+0x68/0x7c [<800b9ef0>] __irq_get_desc_lock+0x60/0x9c [<800bd024>] irq_modify_status+0x30/0xbc [<800b9fe8>] irq_set_percpu_devid+0x74/0x8c [<803cb838>] gic_irq_domain_map+0x64/0x90 [<800bf5d0>] irq_domain_add_legacy+0x114/0x158 [<8093c2b0>] gic_init_bases+0x224/0x3c4 [<8093c528>] gic_of_init+0xd8/0x110 [<809445f0>] of_irq_init+0x184/0x29c [<8093be60>] irqchip_init+0x18/0x1c [<80919ca8>] exynos5_init_irq+0x10/0x28 [<80913fb0>] init_IRQ+0x30/0x34 [<80910a50>] start_kernel+0x244/0x434 [<40008084>] 0x40008084 } ... key at: [<80f288ac>] irq_desc_lock_class+0x0/0x8 ... acquired at: [<8008fa94>] check_usage+0x464/0x648 [<8008fcdc>] check_irq_usage+0x64/0xc0 [<80092e98>] __lock_acquire+0xfbc/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d2050>] exynos_wkup_irq_set_type+0xec/0x190 [<800bbcc8>] __irq_set_trigger+0x64/0x120 [<800bc14c>] __setup_irq+0x3c8/0x4c4 [<800bc39c>] request_threaded_irq+0xbc/0x13c [<800bc478>] request_any_context_irq+0x5c/0x8c [<804e2e48>] gpio_keys_probe+0x2cc/0x83c [<8041df3c>] platform_drv_probe+0x24/0x28 [<8041c9b0>] driver_probe_device+0x118/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<80942488>] gpio_keys_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20
the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&(&(&bank->slock)->lock)->wait_lock){+.+...} ops: 145 { HARDIRQ-ON-W at: [<8008ffa0>] mark_lock+0x180/0x808 [<80092498>] __lock_acquire+0x5bc/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d0594>] samsung_pinconf_rw+0xc8/0x14c [<803d06dc>] samsung_pinconf_group_set+0x70/0x90 [<803cf864>] pinconf_apply_setting+0x90/0x198 [<803cc07c>] pinctrl_select_state+0xf0/0x1a8 [<80436790>] pinctrl_bind_pins+0x7c/0xd4 [<8041c900>] driver_probe_device+0x68/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<809426e0>] i2c_adap_s3c_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20 SOFTIRQ-ON-W at: [<8008ffa0>] mark_lock+0x180/0x808 [<800924c0>] __lock_acquire+0x5e4/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d0594>] samsung_pinconf_rw+0xc8/0x14c [<803d06dc>] samsung_pinconf_group_set+0x70/0x90 [<803cf864>] pinconf_apply_setting+0x90/0x198 [<803cc07c>] pinctrl_select_state+0xf0/0x1a8 [<80436790>] pinctrl_bind_pins+0x7c/0xd4 [<8041c900>] driver_probe_device+0x68/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<809426e0>] i2c_adap_s3c_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20 INITIAL USE at: [<8008ffa0>] mark_lock+0x180/0x808 [<8009219c>] __lock_acquire+0x2c0/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d0594>] samsung_pinconf_rw+0xc8/0x14c [<803d06dc>] samsung_pinconf_group_set+0x70/0x90 [<803cf864>] pinconf_apply_setting+0x90/0x198 [<803cc07c>] pinctrl_select_state+0xf0/0x1a8 [<80436790>] pinctrl_bind_pins+0x7c/0xd4 [<8041c900>] driver_probe_device+0x68/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<809426e0>] i2c_adap_s3c_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20 } ... key at: [<80f6f0ec>] __key.15784+0x0/0x8 ... acquired at: [<8008fad0>] check_usage+0x4a0/0x648 [<8008fcdc>] check_irq_usage+0x64/0xc0 [<80092e98>] __lock_acquire+0xfbc/0x1ec0 [<800943f8>] lock_acquire+0xc4/0x174 [<8068cbd8>] _raw_spin_lock+0x58/0x68 [<8068ba2c>] rt_spin_lock_slowlock+0x54/0x2f8 [<8068c42c>] rt_spin_lock+0x3c/0x68 [<803d2050>] exynos_wkup_irq_set_type+0xec/0x190 [<800bbcc8>] __irq_set_trigger+0x64/0x120 [<800bc14c>] __setup_irq+0x3c8/0x4c4 [<800bc39c>] request_threaded_irq+0xbc/0x13c [<800bc478>] request_any_context_irq+0x5c/0x8c [<804e2e48>] gpio_keys_probe+0x2cc/0x83c [<8041df3c>] platform_drv_probe+0x24/0x28 [<8041c9b0>] driver_probe_device+0x118/0x230 [<8041cbb8>] __driver_attach+0x9c/0xa0 [<8041aad4>] bus_for_each_dev+0x70/0xa4 [<8041c430>] driver_attach+0x2c/0x30 [<8041c048>] bus_add_driver+0x1e0/0x26c [<8041d26c>] driver_register+0x88/0x150 [<8041e620>] platform_driver_register+0x60/0x68 [<80942488>] gpio_keys_init+0x18/0x1c [<800087a4>] do_one_initcall+0x128/0x180 [<80910e40>] kernel_init_freeable+0x200/0x2a0 [<8067b7b0>] kernel_init+0x20/0x170 [<8001f758>] ret_from_fork+0x14/0x20
stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.6-linaro-arndale #1 [<80026578>] (unwind_backtrace+0x0/0x100) from [<80023a90>] (show_stack+0x20/0x24) [<80023a90>] (show_stack+0x20/0x24) from [<80688914>] (dump_stack+0x24/0x28) [<80688914>] (dump_stack+0x24/0x28) from [<8008faf4>] (check_usage+0x4c4/0x648) [<8008faf4>] (check_usage+0x4c4/0x648) from [<8008fcdc>] (check_irq_usage+0x64/0xc0) [<8008fcdc>] (check_irq_usage+0x64/0xc0) from [<80092e98>] (__lock_acquire+0xfbc/0x1ec0) [<80092e98>] (__lock_acquire+0xfbc/0x1ec0) from [<800943f8>] (lock_acquire+0xc4/0x174) [<800943f8>] (lock_acquire+0xc4/0x174) from [<8068cbd8>] (_raw_spin_lock+0x58/0x68) [<8068cbd8>] (_raw_spin_lock+0x58/0x68) from [<8068ba2c>] (rt_spin_lock_slowlock+0x54/0x2f8) [<8068ba2c>] (rt_spin_lock_slowlock+0x54/0x2f8) from [<8068c42c>] (rt_spin_lock+0x3c/0x68) [<8068c42c>] (rt_spin_lock+0x3c/0x68) from [<803d2050>] (exynos_wkup_irq_set_type+0xec/0x190) [<803d2050>] (exynos_wkup_irq_set_type+0xec/0x190) from [<800bbcc8>] (__irq_set_trigger+0x64/0x120) [<800bbcc8>] (__irq_set_trigger+0x64/0x120) from [<800bc14c>] (__setup_irq+0x3c8/0x4c4) [<800bc14c>] (__setup_irq+0x3c8/0x4c4) from [<800bc39c>] (request_threaded_irq+0xbc/0x13c) [<800bc39c>] (request_threaded_irq+0xbc/0x13c) from [<800bc478>] (request_any_context_irq+0x5c/0x8c) [<800bc478>] (request_any_context_irq+0x5c/0x8c) from [<804e2e48>] (gpio_keys_probe+0x2cc/0x83c) [<804e2e48>] (gpio_keys_probe+0x2cc/0x83c) from [<8041df3c>] (platform_drv_probe+0x24/0x28) [<8041df3c>] (platform_drv_probe+0x24/0x28) from [<8041c9b0>] (driver_probe_device+0x118/0x230) [<8041c9b0>] (driver_probe_device+0x118/0x230) from [<8041cbb8>] (__driver_attach+0x9c/0xa0) [<8041cbb8>] (__driver_attach+0x9c/0xa0) from [<8041aad4>] (bus_for_each_dev+0x70/0xa4) [<8041aad4>] (bus_for_each_dev+0x70/0xa4) from [<8041c430>] (driver_attach+0x2c/0x30) [<8041c430>] (driver_attach+0x2c/0x30) from [<8041c048>] (bus_add_driver+0x1e0/0x26c) [<8041c048>] (bus_add_driver+0x1e0/0x26c) from [<8041d26c>] (driver_register+0x88/0x150) [<8041d26c>] (driver_register+0x88/0x150) from [<8041e620>] (platform_driver_register+0x60/0x68) [<8041e620>] (platform_driver_register+0x60/0x68) from [<80942488>] (gpio_keys_init+0x18/0x1c) [<80942488>] (gpio_keys_init+0x18/0x1c) from [<800087a4>] (do_one_initcall+0x128/0x180) [<800087a4>] (do_one_initcall+0x128/0x180) from [<80910e40>] (kernel_init_freeable+0x200/0x2a0) [<80910e40>] (kernel_init_freeable+0x200/0x2a0) from [<8067b7b0>] (kernel_init+0x20/0x170) [<8067b7b0>] (kernel_init+0x20/0x170) from [<8001f758>] (ret_from_fork+0x14/0x20)
Does this happen on linux-next?
Not tried on that, it was tried on 3.10 stable kernel merged with RT patches..
-- viresh
On Fri, Aug 16, 2013 at 05:13:01PM +0530, Viresh Kumar wrote:
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
What about SMP kernels? linux-next?
Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call.
Similar stuff was already done for few other drivers in the past, like:
commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner tglx@linutronix.de Date: Tue May 29 21:53:50 2007 +0100
[ARM] 4417/1: Serial: Fix AMBA drivers lockingThis is neither tested nor compiled.
So I'm guessing you don't want it to be applied, if you can't take the time to at least test-build it, why should we?
{sigh}
I was working on Samsung's Arndale board and so was required to samsung serial driver. Then thought why not others :)
Rebased over: v3.11-rc5
Lots of tty and serial changes have happened since -rc5 in linux-next, can you please rebase, and test, these against that tree and resend them if they are still needed?
thanks,
greg k-h
On 16 August 2013 17:57, Greg KH gregkh@linuxfoundation.org wrote:
On Fri, Aug 16, 2013 at 05:13:01PM +0530, Viresh Kumar wrote:
The -rt patch triggers a lockdep warning for serial drivers if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels.
What about SMP kernels? linux-next?
As per Thomas Gleixner initial patch, it must break for SMP too. But we have tested it only for 3.10 stable merged with RT Kernel patchset..
Haven't tried it on linux-next..
This is neither tested nor compiled.
So I'm guessing you don't want it to be applied, if you can't take the time to at least test-build it, why should we?
{sigh}
:( ..
Actually I build tested it for few ARM platforms but not for others.. Now its build tested for all platforms that are modified here..
Lots of tty and serial changes have happened since -rc5 in linux-next, can you please rebase, and test, these against that tree and resend them if they are still needed?
I have rebased them over latest linux-next and they applied cleanly.. Haven't tested it though.. Will try that next week.
Sorry for the noise :(
-- viresh
On 16 August 2013 23:14, Viresh Kumar viresh.kumar@linaro.org wrote:
On 16 August 2013 17:57, Greg KH gregkh@linuxfoundation.org wrote:
Lots of tty and serial changes have happened since -rc5 in linux-next, can you please rebase, and test, these against that tree and resend them if they are still needed?
I have rebased them over latest linux-next and they applied cleanly.. Haven't tested it though.. Will try that next week.
I initially thought that the problem only occurs with a merge to RT kernel otherwise this would have happened to lots of people..
But when I tried latest linux-next/master (as of today), without RT patch I was able to reproduce the issue on Samsung's Arndale board.
[ 129.179314] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 129.187676] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 129.195619] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [ 129.204247] [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [ 129.214241] [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [ 129.224832] [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [ 129.235336] [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [ 129.245753] [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [ 129.255407] [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [ 129.264636] [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [ 129.274030] [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [ 129.282655] [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [ 129.290938] [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) [ 129.299134] Exception stack(0xc04cdf70 to 0xc04cdfb8) [ 129.304084] df60: 00000000 00000000 0000166e 00000000 [ 129.312117] df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 [ 129.320146] dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [ 129.326639] [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [ 129.334756] [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [ 129.343644] [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) [ 133.343767] BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 [ 133.348574] lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 [ 133.357885] CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 [ 133.366858] Workqueue: events flush_to_ldisc [ 133.371034] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 133.379413] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 133.387355] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [ 133.395982] [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [ 133.405635] [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [ 133.414602] [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [ 133.422973] [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [ 133.432026] [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [ 133.441081] [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [ 133.450048] [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [ 133.459014] [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [ 133.467128] [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c)
And so yes they are required over latest linux-next as well.. I will resend V2 soon. Thanks..
On 08/19/2013 06:43 AM, Viresh Kumar wrote:
On 16 August 2013 23:14, Viresh Kumar viresh.kumar@linaro.org wrote:
On 16 August 2013 17:57, Greg KH gregkh@linuxfoundation.org wrote:
Lots of tty and serial changes have happened since -rc5 in linux-next, can you please rebase, and test, these against that tree and resend them if they are still needed?
I have rebased them over latest linux-next and they applied cleanly.. Haven't tested it though.. Will try that next week.
I initially thought that the problem only occurs with a merge to RT kernel otherwise this would have happened to lots of people..
But when I tried latest linux-next/master (as of today), without RT patch I was able to reproduce the issue on Samsung's Arndale board.
[ 129.179314] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 129.187676] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 129.195619] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [ 129.204247] [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [ 129.214241] [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [ 129.224832] [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [ 129.235336] [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [ 129.245753] [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [ 129.255407] [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [ 129.264636] [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [ 129.274030] [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [ 129.282655] [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [ 129.290938] [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) [ 129.299134] Exception stack(0xc04cdf70 to 0xc04cdfb8) [ 129.304084] df60: 00000000 00000000 0000166e 00000000 [ 129.312117] df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 [ 129.320146] dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [ 129.326639] [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [ 129.334756] [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [ 129.343644] [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) [ 133.343767] BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 [ 133.348574] lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 [ 133.357885] CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 [ 133.366858] Workqueue: events flush_to_ldisc [ 133.371034] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 133.379413] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 133.387355] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [ 133.395982] [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [ 133.405635] [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [ 133.414602] [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [ 133.422973] [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [ 133.432026] [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [ 133.441081] [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [ 133.450048] [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [ 133.459014] [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [ 133.467128] [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c)
And so yes they are required over latest linux-next as well.. I will resend V2 soon. Thanks..
Umm. How did a worker thread schedule while an IRQ handler was holding a irq-disabling spin lock?
Regards, Peter Hurley
PS - please paste your stack backtraces with line-wrap disabled
On 19 August 2013 18:45, Peter Hurley peter@hurleysoftware.com wrote:
Umm. How did a worker thread schedule while an IRQ handler was holding a irq-disabling spin lock?
Not sure.. I was just trying to fix a random issue that came to me. Don't really have much knowledge of serial backend :(
PS - please paste your stack backtraces with line-wrap disabled
I copied it correctly but its gmail which corrupted it.. If I see the text in your reply its fixed automatically :)
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