From: Laurent Pinchart Date: Fri, 11 May 2012 12:55:59 +0000 (-0300) Subject: [media] uvcvideo: Fix V4L2 button controls that share the same UVC control X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=6b363f9f97af10767e72a04c2a5cabfc32133cc4;p=~shefty%2Frdma-dev.git [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 Signed-off-by: Laurent Pinchart Acked-by: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- 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)