The behaviour of the UART poll_put_char infrastructure is inconsistent with respect to linefeed conversions. This in turn leads to difficulty using kdb on serial ports that are not also consoles (e.g. console=ttyAMA0,115200 kgdboc=ttyAMA1,115200).
The following drivers automatically convert '\n' to '\r\n' inside their own poll functions but the remaining seventeen do not:
serial8250, cpm, pch_uart, serial_pxa, serial_txx9,
This can be made fully consistent but performing the conversion in uart_poll_put_char(). A similar conversion is already made inside uart_console_write() but it is optional for drivers to use this function. Fortunately we can be confident the translation is safe because the (very common) 8250 already does this translation.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Cc: Kumar Gala galak@kernel.crashing.org Cc: Pantelis Antoniou panto@intracom.gr Cc: Heikki Krogerus heikki.krogerus@linux.intel.com Cc: Joe Schultz jschultz@xes-inc.com Cc: Loic Poulain loic.poulain@intel.com Cc: Kyle McMartin kyle@infradead.org Cc: Stephen Warren swarren@nvidia.com Cc: Ingo Molnar mingo@elte.hu Cc: Paul Gortmaker paul.gortmaker@windriver.com Cc: Grant Likely grant.likely@linaro.org Cc: Rob Herring rob.herring@calxeda.com Cc: Jingoo Han jg1.han@samsung.com Cc: Christophe Leroy christophe.leroy@c-s.fr --- drivers/tty/serial/8250/8250_core.c | 5 ----- drivers/tty/serial/cpm_uart/cpm_uart_core.c | 8 ++++---- drivers/tty/serial/pch_uart.c | 5 ----- drivers/tty/serial/pxa.c | 5 ----- drivers/tty/serial/serial_core.c | 2 ++ drivers/tty/serial/serial_txx9.c | 5 ----- 6 files changed, 6 insertions(+), 24 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 2d4bd39..053c200 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1926,13 +1926,8 @@ static void serial8250_put_poll_char(struct uart_port *port, wait_for_xmitr(up, BOTH_EMPTY); /* * Send the character out. - * If a LF, also do CR... */ serial_port_out(port, UART_TX, c); - if (c == 10) { - wait_for_xmitr(up, BOTH_EMPTY); - serial_port_out(port, UART_TX, 13); - }
/* * Finally, wait for transmitter to become empty diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c index 7d76214..aa60e6d 100644 --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c @@ -971,7 +971,7 @@ static void cpm_uart_config_port(struct uart_port *port, int flags) * Note that this is called with interrupts already disabled */ static void cpm_uart_early_write(struct uart_cpm_port *pinfo, - const char *string, u_int count) + const char *string, u_int count, bool handle_linefeed) { unsigned int i; cbd_t __iomem *bdp, *bdbase; @@ -1013,7 +1013,7 @@ static void cpm_uart_early_write(struct uart_cpm_port *pinfo, bdp++;
/* if a LF, also do CR... */ - if (*string == 10) { + if (handle_linefeed && *string == 10) { while ((in_be16(&bdp->cbd_sc) & BD_SC_READY) != 0) ;
@@ -1111,7 +1111,7 @@ static void cpm_put_poll_char(struct uart_port *port, static char ch[2];
ch[0] = (char)c; - cpm_uart_early_write(pinfo, ch, 1); + cpm_uart_early_write(pinfo, ch, 1, false); } #endif /* CONFIG_CONSOLE_POLL */
@@ -1275,7 +1275,7 @@ static void cpm_uart_console_write(struct console *co, const char *s, spin_lock_irqsave(&pinfo->port.lock, flags); }
- cpm_uart_early_write(pinfo, s, count); + cpm_uart_early_write(pinfo, s, count, true);
if (unlikely(nolock)) { local_irq_restore(flags); diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index 0931b3f..11e631d 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -1588,13 +1588,8 @@ static void pch_uart_put_poll_char(struct uart_port *port, wait_for_xmitr(priv, UART_LSR_THRE); /* * Send the character out. - * If a LF, also do CR... */ iowrite8(c, priv->membase + PCH_UART_THR); - if (c == 10) { - wait_for_xmitr(priv, UART_LSR_THRE); - iowrite8(13, priv->membase + PCH_UART_THR); - }
/* * Finally, wait for transmitter to become empty diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c index f9f20f3..9e7ee39 100644 --- a/drivers/tty/serial/pxa.c +++ b/drivers/tty/serial/pxa.c @@ -711,13 +711,8 @@ static void serial_pxa_put_poll_char(struct uart_port *port, wait_for_xmitr(up); /* * Send the character out. - * If a LF, also do CR... */ serial_out(up, UART_TX, c); - if (c == 10) { - wait_for_xmitr(up); - serial_out(up, UART_TX, 13); - }
/* * Finally, wait for transmitter to become empty diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index b68550d..50167bf 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2239,6 +2239,8 @@ static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) return;
port = state->uart_port; + if (ch == '\n') + port->ops->poll_put_char(port, '\r'); port->ops->poll_put_char(port, ch); } #endif diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c index 90a080b..60f49b9 100644 --- a/drivers/tty/serial/serial_txx9.c +++ b/drivers/tty/serial/serial_txx9.c @@ -535,13 +535,8 @@ static void serial_txx9_put_poll_char(struct uart_port *port, unsigned char c) wait_for_xmitr(up); /* * Send the character out. - * If a LF, also do CR... */ sio_out(up, TXX9_SITFIFO, c); - if (c == 10) { - wait_for_xmitr(up); - sio_out(up, TXX9_SITFIFO, 13); - }
/* * Finally, wait for transmitter to become empty