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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2012-05-11 09:55:59 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-05-20 10:41:18 -0300
commit6b363f9f97af10767e72a04c2a5cabfc32133cc4 (patch)
tree32d455374f612d6f7b9416678c199733b11117cf /drivers/media/video/uvc
parente2b710bfde37dcc5e5c55fe09e640c1a218a81a2 (diff)
[media] uvcvideo: Fix V4L2 button controls that share the same UVC control
The Logitech pan/tilt reset UVC control contains two V4L2 button controls to reset pan and tilt. As the UVC control is not marked as auto-update, the button bits are set but never reset. A pan reset that follows a tilt reset would thus reset both pan and tilt. Fix this by not caching the control value of write-only controls. All standard UVC controls are either readable or auto-update, so this will not cause any regression and will not result in extra USB requests. Reported-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/uvc')
-rw-r--r--drivers/media/video/uvc/uvc_ctrl.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index f3bd66c500b..af26bbe6f76 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -1351,9 +1351,12 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
/* Reset the loaded flag for auto-update controls that were
* marked as loaded in uvc_ctrl_get/uvc_ctrl_set to prevent
- * uvc_ctrl_get from using the cached value.
+ * uvc_ctrl_get from using the cached value, and for write-only
+ * controls to prevent uvc_ctrl_set from setting bits not
+ * explicitly set by the user.
*/
- if (ctrl->info.flags & UVC_CTRL_FLAG_AUTO_UPDATE)
+ if (ctrl->info.flags & UVC_CTRL_FLAG_AUTO_UPDATE ||
+ !(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
ctrl->loaded = 0;
if (!ctrl->dirty)