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

[ Upstream commit 1d7804281df3f09f0a109d00406e859a00bae7ae ]

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>
Stable-dep-of: 36cef585e2a3 ("media: vimc: skip .s_stream() for stopped entities")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index a32ef739eb44905e8bac031c92b79e8516dab8ee..8bfbe9d5fe3c4469ac19fc9a6cb207c8e7a82f28 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -363,12 +363,8 @@ 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);
@@ -379,7 +375,7 @@ 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 IS_REACHABLE(CONFIG_LEDS_CLASS)
                if (!IS_ERR_OR_NULL(sd->privacy_led)) {

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index ab2a7ef61d420f26bc2fda17b878ec04b273231b..ee570dfbd791daff2a120033a35063425ee222d8 100644 (file)
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1042,6 +1042,8 @@ 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.
@@ -1090,6 +1092,7 @@ struct v4l2_subdev {
         */
        struct v4l2_subdev_state *active_state;
        u64 enabled_streams;
+       bool s_stream_enabled;
 };