diff options
| author | Ricardo Ribalda <ribalda@chromium.org> | 2025-07-01 06:45:17 +0000 |
|---|---|---|
| committer | Hans Verkuil <hverkuil@xs4all.nl> | 2025-07-11 19:27:28 +0200 |
| commit | a03e32e60141058d46ea8cf4631654c43c740fdb (patch) | |
| tree | e721b212946e634153139ab9acc774f1f5562a60 | |
| parent | 7dd56c47784a466b03df62ca766207f483353cdc (diff) | |
media: uvcvideo: Turn on the camera if V4L2_EVENT_SUB_FL_SEND_INITIAL
If we subscribe to an event with V4L2_EVENT_SUB_FL_SEND_INITIAL, the
driver needs to report back some values that require the camera to be
powered on. But VIDIOC_SUBSCRIBE_EVENT is not part of the ioctls that
turn on the camera.
We could unconditionally turn on the camera during
VIDIOC_SUBSCRIBE_EVENT, but it is more efficient to turn it on only
during V4L2_EVENT_SUB_FL_SEND_INITIAL, which we believe is not a common
usecase.
To avoid a list_del if uvc_pm_get() fails, we move list_add_tail to the
end of the function.
Reviewed-by: Hans de Goede <hansg@kernel.org>
Fixes: d1b618e79548 ("media: uvcvideo: Do not turn on the camera for some ioctls")
Cc: stable@vger.kernel.org
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://lore.kernel.org/r/20250701-uvc-grannular-invert-v4-5-8003b9b89f68@chromium.org
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
| -rw-r--r-- | drivers/media/usb/uvc/uvc_ctrl.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 303b7509ec47..efe609d70877 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -2072,18 +2072,24 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems) goto done; } - list_add_tail(&sev->node, &mapping->ev_subs); if (sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL) { struct v4l2_event ev; u32 changes = V4L2_EVENT_CTRL_CH_FLAGS; s32 val = 0; + ret = uvc_pm_get(handle->chain->dev); + if (ret) + goto done; + if (uvc_ctrl_mapping_is_compound(mapping) || __uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0) changes |= V4L2_EVENT_CTRL_CH_VALUE; uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val, changes); + + uvc_pm_put(handle->chain->dev); + /* * Mark the queue as active, allowing this initial event to be * accepted. @@ -2092,6 +2098,8 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems) v4l2_event_queue_fh(sev->fh, &ev); } + list_add_tail(&sev->node, &mapping->ev_subs); + done: mutex_unlock(&handle->chain->ctrl_mutex); return ret; |