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@xxxxxxxxxx>
Cc: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Cc: Pantelis Antoniou <panto@xxxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Joe Schultz <jschultz@xxxxxxxxxxx>
Cc: Loic Poulain <loic.poulain@xxxxxxxxx>
Cc: Kyle McMartin <kyle@xxxxxxxxxxxxx>
Cc: Stephen Warren <swarren@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
---
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
--
1.9.0
--
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