[media] dib8000: make 32 bits read atomic

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As the dvb-frontend kthread can be called anytime, it can race
with some get status ioctl. So, it seems better to avoid one to
race with the other while reading a 32 bits register.
I can't see any other reason for having a mutex there at I2C, except
to provide such kind of protection, as the I2C core already has a
mutex to protect I2C transfers.

Note: instead of this approach, it could eventually remove the dib8000
specific mutex for it, and either group the 4 ops into one xfer or
to manually control the I2C mutex. The main advantage of the current
approach is that the changes are smaller and more puntual.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Acked-by: Patrick Boettcher <pboettcher@kernellabs.com>

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This commit is contained in:

Mauro Carvalho Chehab 2013-12-13 10:35:03 -03:00

parent d67350f8c4

commit 5ac64ba12a

1 changed files with 25 additions and 8 deletions

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drivers/media/dvb-frontends/dib8000.c

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