From: Paul Elder Date: Mon, 9 Sep 2024 15:48:28 +0000 (+0200) Subject: media: platform: video-mux: Fix mutex locking X-Git-Tag: v6.13-rc1~149^2~120 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ee5e1fd82950743ecb9f6c99bd240098a9c6307;p=thirdparty%2Flinux.git media: platform: video-mux: Fix mutex locking The current order of locking between the driver mutex and the v4l2 subdev state lock causes a circular locking dependency when trying to set up a link. Fix this. Signed-off-by: Paul Elder Reviewed-by: Laurent Pinchart [Sakari Ailus: Fix spelling in commit message.] Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/platform/video-mux.c b/drivers/media/platform/video-mux.c index 5748aff8fc40b..cba34893258a8 100644 --- a/drivers/media/platform/video-mux.c +++ b/drivers/media/platform/video-mux.c @@ -52,6 +52,7 @@ static int video_mux_link_setup(struct media_entity *entity, const struct media_pad *remote, u32 flags) { struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity); + struct v4l2_subdev_state *sd_state; struct video_mux *vmux = v4l2_subdev_to_video_mux(sd); u16 source_pad = entity->num_pads - 1; int ret = 0; @@ -67,10 +68,10 @@ static int video_mux_link_setup(struct media_entity *entity, remote->entity->name, remote->index, local->entity->name, local->index, flags & MEDIA_LNK_FL_ENABLED); + sd_state = v4l2_subdev_lock_and_get_active_state(sd); mutex_lock(&vmux->lock); if (flags & MEDIA_LNK_FL_ENABLED) { - struct v4l2_subdev_state *sd_state; struct v4l2_mbus_framefmt *source_mbusformat; if (vmux->active == local->index) @@ -88,12 +89,10 @@ static int video_mux_link_setup(struct media_entity *entity, vmux->active = local->index; /* Propagate the active format to the source */ - sd_state = v4l2_subdev_lock_and_get_active_state(sd); source_mbusformat = v4l2_subdev_state_get_format(sd_state, source_pad); *source_mbusformat = *v4l2_subdev_state_get_format(sd_state, vmux->active); - v4l2_subdev_unlock_state(sd_state); } else { if (vmux->active != local->index) goto out; @@ -105,6 +104,7 @@ static int video_mux_link_setup(struct media_entity *entity, out: mutex_unlock(&vmux->lock); + v4l2_subdev_unlock_state(sd_state); return ret; }