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From:   Ricardo Ribalda <ribalda@chromium.org>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Tomasz Figa <tfiga@chromium.org>, linux-media@vger.kernel.org,
        linux-kernel@vger.kernel.org, senozhatsky@chromium.org,
        Hans Verkuil <hverkuil@xs4all.nl>
Cc:     Ricardo Ribalda <ribalda@chromium.org>
Subject: [PATCH v2 4/6] media: uvcvideo: set error_idx to count on EACCESS
Date:   Thu, 11 Mar 2021 23:19:44 +0100
Message-Id: <20210311221946.1319924-5-ribalda@chromium.org>
In-Reply-To: <20210311221946.1319924-1-ribalda@chromium.org>
References: <20210311221946.1319924-1-ribalda@chromium.org>
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According to the doc:
The, in hindsight quite poor, solution for that is to set error_idx to
count if the validation failed.

Fixes v4l2-compliance:
Control ioctls (Input 0):
                fail: v4l2-test-controls.cpp(645): invalid error index write only control
        test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 157310c0ca87..36eb48622d48 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1073,7 +1073,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 		ret = uvc_ctrl_get(chain, ctrl);
 		if (ret < 0) {
 			uvc_ctrl_rollback(handle);
-			ctrls->error_idx = i;
+			ctrls->error_idx = (ret == -EACCES) ?
+						ctrls->count : i;
 			return ret;
 		}
 	}
-- 
2.31.0.rc2.261.g7f71774620-goog