[for,v6.1] vivid: fix control handler mutex deadlock

Commit Message

Hans Verkuil Oct. 21, 2022, 12:21 p.m. UTC

vivid_update_format_cap() can be called from an s_ctrl callback.
In that case (keep_controls == true) no control framework functions
can be called that take the control handler mutex.

The new call to v4l2_ctrl_modify_dimensions() did exactly that.

Signed-off-by: Hans Verkuil <[e-mail]>
Fixes: 6bc7643d1b9c (media: vivid: add pixel_array test control)
---
 drivers/media/test-drivers/vivid/vivid-vid-cap.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/drivers/media/test-drivers/vivid/vivid-vid-cap.c b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
index 86b158eeb2d8..8ae43da9bfba 100644
--- a/drivers/media/test-drivers/vivid/vivid-vid-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
@@ -460,6 +460,14 @@  void vivid_update_format_cap(struct vivid_dev *dev, bool keep_controls)
 	tpg_s_video_aspect(&dev->tpg, vivid_get_video_aspect(dev));
 	tpg_s_pixel_aspect(&dev->tpg, vivid_get_pixel_aspect(dev));
 	tpg_update_mv_step(&dev->tpg);
+
+	/*
+	 * We can be called from within s_ctrl, in that case we can't
+	 * modify controls. Luckily we don't need to in that case.
+	 */
+	if (keep_controls)
+		return;
+
 	dims[0] = roundup(dev->src_rect.width, PIXEL_ARRAY_DIV);
 	dims[1] = roundup(dev->src_rect.height, PIXEL_ARRAY_DIV);
 	v4l2_ctrl_modify_dimensions(dev->pixel_array, dims);