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media: subdev: Fix use of sd->enabled_streams in call_s_stream()

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call_s_stream() uses sd->enabled_streams to track whether streaming has
already been enabled. However,
v4l2_subdev_enable/disable_streams_fallback(), which was the original
user of this field, already uses it, and
v4l2_subdev_enable/disable_streams_fallback() will call call_s_stream().

This leads to a conflict as both functions set the field. Afaics, both
functions set the field to the same value, so it won't cause a runtime
bug, but it's still wrong and if we, e.g., change how
v4l2_subdev_enable/disable_streams_fallback() operates we might easily
cause bugs.

Fix this by adding a new field, 's_stream_enabled', for
call_s_stream().

Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
This commit is contained in:
Tomi Valkeinen 2024-04-24 18:39:07 +03:00 committed by Hans Verkuil
parent e003fd9c1e
commit 1d7804281d
2 changed files with 5 additions and 6 deletions
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8
drivers/media/v4l2-core/v4l2-subdev.c
View File

@ -451,12 +451,8 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable)
* The .s_stream() operation must never be called to start or stop an
* already started or stopped subdev. Catch offenders but don't return
* an error yet to avoid regressions.
*
* As .s_stream() is mutually exclusive with the .enable_streams() and
* .disable_streams() operation, we can use the enabled_streams field
* to store the subdev streaming state.
*/
if (WARN_ON(!!sd->enabled_streams == !!enable))
if (WARN_ON(sd->s_stream_enabled == !!enable))
return 0;
ret = sd->ops->video->s_stream(sd, enable);
@ -467,7 +463,7 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable)
}
if (!ret) {
sd->enabled_streams = enable ? BIT(0) : 0;
sd->s_stream_enabled = enable;
if (enable)
v4l2_subdev_enable_privacy_led(sd);

3
include/media/v4l2-subdev.h
View File

@ -1045,6 +1045,8 @@ struct v4l2_subdev_platform_data {
* v4l2_subdev_enable_streams() and
* v4l2_subdev_disable_streams() helper functions for fallback
* cases.
* @s_stream_enabled: Tracks whether streaming has been enabled with s_stream.
* This is only for call_s_stream() internal use.
*
* Each instance of a subdev driver should create this struct, either
* stand-alone or embedded in a larger struct.
@ -1093,6 +1095,7 @@ struct v4l2_subdev {
*/
struct v4l2_subdev_state *active_state;
u64 enabled_streams;
bool s_stream_enabled;
};