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H A D | v4l2-subdev.c | 3cc7a4bb Tue Apr 12 04:42:45 CDT 2022 Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> media: subdev: pass also the active state to subdevs from ioctls
At the moment when a subdev op is called, the TRY subdev state (subdev_fh->state) is passed as a parameter even for the ACTIVE case, or alternatively a NULL can be passed for ACTIVE case. This used to make sense, as the ACTIVE state was handled internally by the subdev drivers.
We now have a state for the ACTIVE case in a standard place, and can pass that also to the drivers. This patch changes the subdev ioctls to either pass the TRY or ACTIVE state to the subdev.
Unfortunately many drivers call ops from other subdevs, and implicitly pass NULL as the state, so this is just a partial solution. A coccinelle spatch could perhaps be created which fixes the drivers' subdev calls.
For all current upstream drivers this doesn't matter, as they do not expect to get a valid state for ACTIVE case. But future drivers which support multiplexed streaming and routing will depend on getting a state for both active and try cases.
For new drivers we can mandate that the pipelines where the drivers are used need to pass the state properly, or preferably, not call such subdev ops at all.
However, if an existing subdev driver is changed to support multiplexed streams, the driver has to consider cases where its ops will be called with NULL state. The problem can easily be solved by using the v4l2_subdev_lock_and_get_active_state() helper, introduced in a follow up patch.
Another follow up patch adds wrappers for pad ops dealing with subdev state, which automate the use of v4l2_subdev_lock_and_get_active_state() for cases where the state is NULL.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
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