5.4-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
[ 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@kernel.org Link: https://lore.kernel.org/r/20210407102334.32361-8-johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: fe0ebeafc3b7 ("staging: greybus: uart: Fix atomicity violation in get_serial_info()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/greybus/uart.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c index 0e6bebc20695d..b8da6dc5d4d4d 100644 --- a/drivers/staging/greybus/uart.c +++ b/drivers/staging/greybus/uart.c @@ -621,10 +621,7 @@ 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 ?