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| author | Marek Roszko <mark.roszko@gmail.com> | 2014-01-10 10:33:11 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-13 15:55:59 -0800 |
| commit | 8bc661bfc0c2d221e209f4205bdaaf574d50100c (patch) | |
| tree | 2fbd2b8a47104ebc014476530806b1afbbe2f2f5 /arch | |
| parent | 3685f19e07802ec4207b52465c408f185b66490e (diff) | |
| download | lwn-8bc661bfc0c2d221e209f4205bdaaf574d50100c.tar.gz lwn-8bc661bfc0c2d221e209f4205bdaaf574d50100c.zip | |
tty/serial: at91: disable uart timer at start of shutdown
The uart timer will schedule a tasklet when it fires. It is possible that it
can fire inside _shutdown before it is killed in the dma and pdc cleanup
routines. This causes a tasklet that exists after the port is shutdown, so when
the kernel finally executes it, it panics as the tty port is NULL.
This is a somewhat rare condition but its possible if a program keeps on
opening/closing the port. It has been observed in particular with systemd
boot messages that were causing a kernel panic because of this behavior.
Moving the timer deletion to the beginning of the function stops a tasklet from
being scheduled unexpectedly.
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Cc: stable <stable@vger.kernel.org> # v3.12
[nicolas.ferre@atmel.com: modify commit message, call setup_timer() in any case]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions