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[v2,3/3] uvcvideo: Set error_idx properly for S_EXT_CTRLS failures

Message ID 1357911233-31664-4-git-send-email-laurent.pinchart@ideasonboard.com (mailing list archive)
State New, archived
Headers show

Commit Message

Laurent Pinchart Jan. 11, 2013, 1:33 p.m. UTC 
The uvc_set_ctrl() calls don't write to the hardware. A failure at that
point thus leaves the device in a clean state, with no control modified.
Set the error_idx field to the count value to reflect that, as per the
V4L2 specification.

TRY_EXT_CTRLS is unchanged and the error_idx field must always be set to
the failed control index in that case.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/usb/uvc/uvc_v4l2.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
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Patch

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 5eb8989..68d59b5 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -685,7 +685,8 @@  static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 			ret = uvc_ctrl_set(chain, ctrl);
 			if (ret < 0) {
 				uvc_ctrl_rollback(handle);
-				ctrls->error_idx = i;
+				ctrls->error_idx = cmd == VIDIOC_S_EXT_CTRLS
+						 ? ctrls->count : i;
 				return ret;
 			}
 		}