On 11/04/2024 08:16, Umang Jain wrote:
Hi Tomi,
Thank you for the patch
On 10/04/24 6:05 pm, Tomi Valkeinen wrote:
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, 'streaming_enabled', for
call_s_stream().
Just a suggestion, as this is only used in call_s_stream(), maybe naming
this field 's_stream_enabled' ?
Yes, I think that's a good idea.
Tomi
Rest looks good to me,
Reviewed-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-subdev.c | 8 ++------
include/media/v4l2-subdev.h | 3 +++
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c
b/drivers/media/v4l2-core/v4l2-subdev.c
index 606a909cd778..6cd353d83dfc 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -421,12 +421,8 @@ 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->streaming_enabled == !!enable))
return 0;
ret = sd->ops->video->s_stream(sd, enable);
@@ -437,7 +433,7 @@ static int call_s_stream(struct v4l2_subdev *sd,
int enable)
}
if (!ret) {
- sd->enabled_streams = enable ? BIT(0) : 0;
+ sd->streaming_enabled = enable;
if (enable)
v4l2_subdev_enable_privacy_led(sd);
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index a9e6b8146279..f55d03e0acc1 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1043,6 +1043,8 @@ struct v4l2_subdev_platform_data {
* v4l2_subdev_enable_streams() and
* v4l2_subdev_disable_streams() helper functions for
fallback
* cases.
+ * @streaming_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.
@@ -1091,6 +1093,7 @@ struct v4l2_subdev {
*/
struct v4l2_subdev_state *active_state;
u64 enabled_streams;
+ bool streaming_enabled;
};
