]> www.infradead.org Git - users/jedix/linux-maple.git/commit
tty: fix termios input-speed encoding when using BOTHER
authorJohan Hovold <johan@kernel.org>
Sun, 15 Jul 2018 13:39:34 +0000 (15:39 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 26 Sep 2018 06:38:11 +0000 (08:38 +0200)
commit3c11fe1edaff491fd43fc9270282e04981621d99
treeb60a401e95c48e64a1ba78f63ec0a8dcf11fa334
parented3151e4221452a77305e28ba1728db84bc08429
tty: fix termios input-speed encoding when using BOTHER

[ Upstream commit 1cee38f0363a88db374e50b232ca17b9a4c12fa0 ]

When the termios CIBAUD bits are left unset (i.e. B0), we use the same
output and input speed and should leave CIBAUD unchanged.

When the user requests a rate using BOTHER and c_ospeed which the driver
cannot set exactly, the driver can report back the actual baud rate
using tty_termios_encode_baud_rate(). If this rate is close enough to a
standard rate however, we could end up setting CIBAUD to a Bfoo value
despite the user having left it unset.

This in turn could lead to an unexpected input rate being set on
subsequent termios updates.

Fix this by using a zero tolerance value also for the input rate when
CIBAUD is clear so that the matching logic works as expected.

Fixes: 78137e3b34e1 ("[PATCH] tty: improve encode_baud_rate logic")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/tty_baudrate.c