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From:   Ricardo Ribalda <ribalda@chromium.org>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        tfiga@chromium.org
Cc:     Ricardo Ribalda <ribalda@chromium.org>,
        Hans Verkuil <hans.verkuil@cisco.com>
Subject: [PATCH 2/4] media: uvcvideo: improve error logging in uvc_query_ctrl()
Date:   Thu,  9 Sep 2021 17:00:44 +0200
Message-Id: <20210909150046.57615-3-ribalda@chromium.org>
In-Reply-To: <20210909150046.57615-1-ribalda@chromium.org>
References: <20210909150046.57615-1-ribalda@chromium.org>
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From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

If __uvc_query_ctrl() failed with a non-EPIPE error, then
report that with dev_err. If an error code is obtained, then
report that with dev_dbg.

Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/usb/uvc/uvc_video.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 9f37eaf28ce7..dfea967309f2 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -79,13 +79,14 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	if (likely(ret == size))
 		return 0;
 
-	dev_err(&dev->udev->dev,
-		"Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n",
-		uvc_query_name(query), cs, unit, ret, size);
-
-	if (ret != -EPIPE)
+	if (ret != -EPIPE) {
+		dev_err(&dev->udev->dev,
+			"Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n",
+			uvc_query_name(query), cs, unit, ret, size);
 		return ret;
+	}
 
+	/* reuse data[0] to request the error code. */
 	tmp = *(u8 *)data;
 
 	ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
-- 
2.33.0.153.gba50c8fa24-goog