Since commit 5d0360a4f027576e5419d4a7c711c9ca0f1be8ca 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@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # for v3.17 and up
---
Hi,
I did check the patch with scripts/checkpatch.pl but it gives an error,
I think it's a false positive.
Ciao ciao,
Antonio
drivers/media/v4l2-core/v4l2-ctrls.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index b6b7dcc..19fc06e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3043,7 +3043,7 @@ static void update_from_auto_cluster(struct v4l2_ctrl *master)
{
int i;
- for (i = 0; i < master->ncontrols; i++)
+ for (i = 1; i < master->ncontrols; i++)
cur_to_new(master->cluster[i]);
if (!call_op(master, g_volatile_ctrl))
for (i = 1; i < master->ncontrols; i++)
--
2.6.1
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