Since commit 5d0360a4f0 it's not possible
anymore to set auto clusters from auto to manual using VIDIOC_S_CTRL.
For example, setting autogain to manual with gspca/ov534 driver and this
sequence of commands does not work:
v4l2-ctl --set-ctrl=gain_automatic=1
v4l2-ctl --list-ctrls | grep gain_automatic
# The following does not work
v4l2-ctl --set-ctrl=gain_automatic=0
v4l2-ctl --list-ctrls | grep gain_automatic
Changing the value using VIDIOC_S_EXT_CTRLS (like qv4l2 does) works
fine.
The apparent cause by looking at the changes in 5d0360a and comparing
with the code path for VIDIOC_S_EXT_CTRLS seems to be that the code in
v4l2-ctrls.c::set_ctrl() is not calling user_to_new() anymore after
calling update_from_auto_cluster(master).
However the root cause of the problem is that calling
update_from_auto_cluster(master) overrides also the _master_ control
state calling cur_to_new() while it was supposed to only update the
volatile controls.
Calling user_to_new() after update_from_auto_cluster(master) was just
masking the original bug by restoring the correct new value of the
master control before making the changes permanent.
Fix the original bug by making update_from_auto_cluster() not override
the new master control value.
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Cc: <stable@vger.kernel.org> # for v3.17 and up
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
759b26a1d9