Hi Mathis,

Thank you for the patch.

On Fri, Mar 07, 2025 at 10:31:39AM +0100, Mathis Foerst wrote:

Getting / Setting the frame interval using the V4L2 subdev pad ops get_frame_interval/set_frame_interval causes a deadlock, as the subdev state is locked in the [1] but also in the driver itself.

In [2] it's described that the caller is responsible to acquire and release the lock in this case. Therefore, acquiring the lock in the driver is wrong.

Remove the lock acquisitions/releases from mt9m114_ifp_get_frame_interval() and mt9m114_ifp_set_frame_interval().

[1] drivers/media/v4l2-core/v4l2-subdev.c - line 1129 [2] Documentation/driver-api/media/v4l2-subdev.rst

Fixes: 24d756e914fc ("media: i2c: Add driver for onsemi MT9M114 camera sensor") Cc: stable@vger.kernel.org

You can delete this blank line.

Signed-off-by: Mathis Foerst mathis.foerst@mt.com

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

---

drivers/media/i2c/mt9m114.c | 8 -------- 1 file changed, 8 deletions(-)

diff --git a/drivers/media/i2c/mt9m114.c b/drivers/media/i2c/mt9m114.c index 65b9124e464f..79c97ab19be9 100644 --- a/drivers/media/i2c/mt9m114.c +++ b/drivers/media/i2c/mt9m114.c @@ -1644,13 +1644,9 @@ static int mt9m114_ifp_get_frame_interval(struct v4l2_subdev *sd, if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE) return -EINVAL;

• mutex_lock(sensor->ifp.hdl.lock);
• ival->numerator = 1; ival->denominator = sensor->ifp.frame_rate;

• mutex_unlock(sensor->ifp.hdl.lock);
• return 0;

} @@ -1669,8 +1665,6 @@ static int mt9m114_ifp_set_frame_interval(struct v4l2_subdev *sd, if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE) return -EINVAL;

• mutex_lock(sensor->ifp.hdl.lock);
• if (ival->numerator != 0 && ival->denominator != 0) sensor->ifp.frame_rate = min_t(unsigned int, ival->denominator / ival->numerator,

@@ -1684,8 +1678,6 @@ static int mt9m114_ifp_set_frame_interval(struct v4l2_subdev *sd, if (sensor->streaming) ret = mt9m114_set_frame_rate(sensor);

• mutex_unlock(sensor->ifp.hdl.lock);
• return ret;

}