lkml.org 
[lkml]   [2016]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.3 093/200] [media] media/v4l2-ctrls: fix setting autocluster to manual with VIDIOC_S_CTRL
    Date
    4.3-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Antonio Ospite <ao2@ao2.it>

    commit 759b26a1d916400a1a20948eb964dea6ad0bd9e9 upstream.

    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@ao2.it>
    Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
    Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/media/v4l2-core/v4l2-ctrls.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- 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(str
    {
    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++)

    \
     
     \ /
      Last update: 2016-02-15 00:21    [W:4.196 / U:0.440 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site