media: chips-media: wave5: Avoid race condition in the interrupt handler

commit ac35f768 upstream.

In case of multiple active instances, new interrupts can occur as soon
as the current interrupt is cleared. If the driver reads the
instance_info after clearing the interrupt, then there is no guarantee,
that the instance_info is still valid for the current interrupt.

Read the instance_info register for each interrupt before clearing the
interrupt.

Fixes: ed7276ed ("media: chips-media: wave5: Add hrtimer based polling support")
Cc: stable@vger.kernel.org
Signed-off-by: Jackson.lee <jackson.lee@chipsnmedia.com>
Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>