Before commit 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") the SER_RS485_RX_DURING_TX flag was only set if the rx-during-tx mode was not controlled by a GPIO. Now the flag is set unconditionally when RS485 is enabled. This results in an incorrect setting if the rx-during-tx GPIO is not asserted.
Fix this by setting the flag only if the rx-during-tx mode is not controlled by a GPIO and thus restore the correct behaviour.
Cc: stable@vger.kernel.org # 6.6+ Fixes: 07c30ea5861f ("serial: Do not hold the port lock when setting rx-during-tx GPIO") Signed-off-by: Lino Sanfilippo l.sanfilippo@kunbus.com --- drivers/tty/serial/stm32-usart.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 794b77512740..693e932d6feb 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -251,7 +251,9 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter writel_relaxed(cr3, port->membase + ofs->cr3); writel_relaxed(cr1, port->membase + ofs->cr1);
- rs485conf->flags |= SER_RS485_RX_DURING_TX; + if (!port->rs485_rx_during_tx_gpio) + rs485conf->flags |= SER_RS485_RX_DURING_TX; + } else { stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DEM | USART_CR3_DEP);
base-commit: 841c35169323cd833294798e58b9bf63fa4fa1de
When DMA is used in RS485 mode make sure that the UARTs tx section is enabled before the DMA buffers are queued for transmission.
Cc: stable@vger.kernel.org Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Signed-off-by: Lino Sanfilippo l.sanfilippo@kunbus.com --- drivers/tty/serial/amba-pl011.c | 60 ++++++++++++++++----------------- 1 file changed, 30 insertions(+), 30 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index fccec1698a54..cf2c890a560f 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1339,11 +1339,41 @@ static void pl011_start_tx_pio(struct uart_amba_port *uap) } }
+static void pl011_rs485_tx_start(struct uart_amba_port *uap) +{ + struct uart_port *port = &uap->port; + u32 cr; + + /* Enable transmitter */ + cr = pl011_read(uap, REG_CR); + cr |= UART011_CR_TXE; + + /* Disable receiver if half-duplex */ + if (!(port->rs485.flags & SER_RS485_RX_DURING_TX)) + cr &= ~UART011_CR_RXE; + + if (port->rs485.flags & SER_RS485_RTS_ON_SEND) + cr &= ~UART011_CR_RTS; + else + cr |= UART011_CR_RTS; + + pl011_write(cr, uap, REG_CR); + + if (port->rs485.delay_rts_before_send) + mdelay(port->rs485.delay_rts_before_send); + + uap->rs485_tx_started = true; +} + static void pl011_start_tx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
+ if ((uap->port.rs485.flags & SER_RS485_ENABLED) && + !uap->rs485_tx_started) + pl011_rs485_tx_start(uap); + if (!pl011_dma_tx_start(uap)) pl011_start_tx_pio(uap); } @@ -1424,42 +1454,12 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c, return true; }
-static void pl011_rs485_tx_start(struct uart_amba_port *uap) -{ - struct uart_port *port = &uap->port; - u32 cr; - - /* Enable transmitter */ - cr = pl011_read(uap, REG_CR); - cr |= UART011_CR_TXE; - - /* Disable receiver if half-duplex */ - if (!(port->rs485.flags & SER_RS485_RX_DURING_TX)) - cr &= ~UART011_CR_RXE; - - if (port->rs485.flags & SER_RS485_RTS_ON_SEND) - cr &= ~UART011_CR_RTS; - else - cr |= UART011_CR_RTS; - - pl011_write(cr, uap, REG_CR); - - if (port->rs485.delay_rts_before_send) - mdelay(port->rs485.delay_rts_before_send); - - uap->rs485_tx_started = true; -} - /* Returns true if tx interrupts have to be (kept) enabled */ static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq) { struct circ_buf *xmit = &uap->port.state->xmit; int count = uap->fifosize >> 1;
- if ((uap->port.rs485.flags & SER_RS485_ENABLED) && - !uap->rs485_tx_started) - pl011_rs485_tx_start(uap); - if (uap->port.x_char) { if (!pl011_tx_char(uap, uap->port.x_char, from_irq)) return true;
linux-stable-mirror@lists.linaro.org
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Lino Sanfilippo