From c4d99f89e20c87c8e2a992ce4cf9aa4325dc7fa7 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Thu, 30 Sep 2010 09:04:03 -0300 Subject: [PATCH] [media] uvcvideo: Ignore GET_RES error for XU controls GET_RES request support is mandatory for extension units, but some cameras still choke on it (one example is the Logitech QuickCam PTZ that returns a single byte for the PTZ relative control instead of four). Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_ctrl.c | 17 +++++++++++++++-- drivers/media/video/uvc/uvcvideo.h | 1 + 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c index 254d32688843..3e849d977bd4 100644 --- a/drivers/media/video/uvc/uvc_ctrl.c +++ b/drivers/media/video/uvc/uvc_ctrl.c @@ -878,8 +878,21 @@ static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain, chain->dev->intfnum, ctrl->info.selector, uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES), ctrl->info.size); - if (ret < 0) - return ret; + if (ret < 0) { + if (UVC_ENTITY_TYPE(ctrl->entity) != + UVC_VC_EXTENSION_UNIT) + return ret; + + /* GET_RES is mandatory for XU controls, but some + * cameras still choke on it. Ignore errors and set the + * resolution value to zero. + */ + uvc_warn_once(chain->dev, UVC_WARN_XU_GET_RES, + "UVC non compliance - GET_RES failed on " + "an XU control. Enabling workaround.\n"); + memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES), 0, + ctrl->info.size); + } } ctrl->cached = 1; diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h index 882159aab610..2b84cbb49665 100644 --- a/drivers/media/video/uvc/uvcvideo.h +++ b/drivers/media/video/uvc/uvcvideo.h @@ -477,6 +477,7 @@ struct uvc_driver { #define UVC_WARN_MINMAX 0 #define UVC_WARN_PROBE_DEF 1 +#define UVC_WARN_XU_GET_RES 2 extern unsigned int uvc_clock_param; extern unsigned int uvc_no_drop_param; -- 2.20.1