V4L2 drivers: potentially dangerous and inefficientmsecs_to_jiffies() calculation

[Andreas Mohr]

Hi all,

./drivers/media/video/sn9c102/sn9c102_core.c
,
./drivers/media/video/et61x251/et61x251_core.c
and
./drivers/media/video/zc0301/zc0301_core.c
do
                            cam->module_param.frame_timeout *
                            1000 * msecs_to_jiffies(1) );
multiple times each.
What they should do instead is
frame_timeout * msecs_to_jiffies(1000), I'd think.
msecs_to_jiffies(1) is quite a bit too boldly assuming
that all of the msecs_to_jiffies(x) implementation branches
always round up.

Not to mention that the current implementation needs one additional
multiplication operation as opposed to constant-aggregating it into the
msecs_to_jiffies() argument and thus nicely evaporating it into nirvana.

HTH,

Andreas Mohr
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