From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
To: Ricardo Ribalda <ribalda@chromium.org>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>
Subject: [PATCH] uvcvideo: improve error handling in uvc_query_ctrl()
Date: Mon, 22 Mar 2021 13:05:45 +0100 [thread overview]
Message-ID: <347cdb4a-19a2-98ce-580f-5aba4abfb2fc@xs4all.nl> (raw)
- 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.
- For error 2 (Wrong state) return -EACCES instead of -EILSEQ.
EACCES is a much more appropriate error code. EILSEQ will return
"Invalid or incomplete multibyte or wide character." in strerror(),
which is a *very* confusing message.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
Ricardo, this too can be added to the uvc series.
---
drivers/media/usb/uvc/uvc_video.c | 44 +++++++++++++++++--------------
1 file changed, 24 insertions(+), 20 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index b63c073ec30e..3f461bb4eeb9 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -68,7 +68,7 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
u8 intfnum, u8 cs, void *data, u16 size)
{
int ret;
- u8 error;
+ u8 error = 0;
u8 tmp;
ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
@@ -76,35 +76,39 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
if (likely(ret == size))
return 0;
- dev_dbg(&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);
+ ret = ret < 0 ? ret : -EPIPE;
- if (ret != -EPIPE)
- return ret;
-
- tmp = *(u8 *)data;
+ if (ret == -EPIPE) {
+ tmp = *(u8 *)data;
- ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
- UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1,
- UVC_CTRL_CONTROL_TIMEOUT);
+ ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
+ UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1,
+ UVC_CTRL_CONTROL_TIMEOUT);
- error = *(u8 *)data;
- *(u8 *)data = tmp;
+ if (ret == 1)
+ error = *(u8 *)data;
+ *(u8 *)data = tmp;
+ if (ret != 1)
+ ret = ret < 0 ? ret : -EPIPE;
+ }
- if (ret != 1)
- return ret < 0 ? ret : -EPIPE;
+ if (error)
+ dev_dbg(&dev->udev->dev,
+ "Failed to query (%s) UVC control %u on unit %u: got error %u.\n",
+ uvc_query_name(query), cs, unit, error);
+ else
+ 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);
- uvc_dbg(dev, CONTROL, "Control error %u\n", error);
+ if (!error)
+ return ret;
switch (error) {
- case 0:
- /* Cannot happen - we received a STALL */
- return -EPIPE;
case 1: /* Not ready */
return -EBUSY;
case 2: /* Wrong state */
- return -EILSEQ;
+ return -EACCES;
case 3: /* Power */
return -EREMOTE;
case 4: /* Out of range */
--
2.30.0
next reply other threads:[~2021-03-22 12:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 12:05 Hans Verkuil [this message]
2021-03-23 15:25 ` [PATCH] uvcvideo: improve error handling in uvc_query_ctrl() Ricardo Ribalda Delgado
2021-03-25 12:18 ` Hans Verkuil
2021-03-25 13:54 ` Ricardo Ribalda
2021-03-25 13:57 ` Hans Verkuil
2021-03-25 14:02 ` Ricardo Ribalda
2021-03-25 14:03 ` Hans Verkuil
2021-03-25 15:56 ` Ricardo Ribalda Delgado
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