This is a note to let you know that I've just added the patch titled
staging: greybus: uart: clean up TIOCGSERIAL
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
staging-greybus-uart-clean-up-tiocgserial.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3c894fa939bbe56314fa7c33ece04c809acb1565
Author: Johan Hovold <johan@xxxxxxxxxx>
Date: Wed Apr 7 12:23:25 2021 +0200
staging: greybus: uart: clean up TIOCGSERIAL
[ Upstream commit d38be702452137fa82a56ff7cc577d829add1637 ]
TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.
The xmit_fifo_size parameter could be used to set the hardware transmit
fifo size of a legacy UART when it could not be detected, but the
interface is limited to eight bits and should be left unset when not
used.
Similarly, baud_base could be used to set the UART base clock when it
could not be detected but might as well be left unset when it is not
known.
The type parameter could be used to set the UART type, but is
better left unspecified (type unknown) when it isn't used.
Note that some applications have historically expected TIOCGSERIAL to be
implemented, but judging from the Debian sources, the port type not
being PORT_UNKNOWN is only used to check for the existence of legacy
serial ports (ttySn). Notably USB serial drivers like ftdi_sio have been
using PORT_UNKNOWN for twenty years without any problems.
Drop the bogus values provided by the greybus implementation.
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210407102334.32361-8-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: fe0ebeafc3b7 ("staging: greybus: uart: Fix atomicity violation in get_serial_info()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c
index edaa83a693d27..5cdc5dff9f55b 100644
--- a/drivers/staging/greybus/uart.c
+++ b/drivers/staging/greybus/uart.c
@@ -610,10 +610,7 @@ static int get_serial_info(struct tty_struct *tty,
{
struct gb_tty *gb_tty = tty->driver_data;
- ss->type = PORT_16550A;
ss->line = gb_tty->minor;
- ss->xmit_fifo_size = 16;
- ss->baud_base = 9600;
ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10;
ss->closing_wait =
gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
