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author | Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> | 2023-12-13 18:00:03 +0300 |
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committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2023-12-13 18:52:34 +0300 |
commit | 08e5c36410ca5cb14237e47e6dfe3fde02e0f275 (patch) | |
tree | b37a5761e3a4164458e3f45b952bbdbe9a128b09 /drivers/media/i2c/et8ek8/et8ek8_driver.c | |
parent | e4af84f34c5a7e951464ab51021764c7c1204d70 (diff) | |
download | linux-08e5c36410ca5cb14237e47e6dfe3fde02e0f275.tar.xz |
media: v4l: subdev: Move out subdev state lock macros outside CONFIG_MEDIA_CONTROLLER
The subdev state locking macros and macros to get the active state are
currently behind CONFIG_MEDIA_CONTROLLER. This makes sense, as there can
be no subdev state without MC.
However, we have code paths common to MC and non-MC cases which call
subdev operations that have subdev state as a parameter. In the non-MC
case the state parameter would always be NULL.
Thus it makes sense to allow, e.g.:
v4l2_subdev_call_state_active(sd, pad, get_fmt, fmt)
which for non-MC case would call the subdev passing NULL as the state.
This currently fails:
https://lore.kernel.org/oe-kbuild-all/202312061101.PLrz5NnJ-lkp@intel.com/
Fix the issue by moving the related macros to be outside
CONFIG_MEDIA_CONTROLLER. The v4l2_subdev_lock_state() and
v4l2_subdev_unlock_state() macros will crash if given NULL as the state,
but the other macros behave correctly even when there's no active state,
and they will only call the lock/unlock macros if there is a state.
An alternative fix would be to make another version of
v4l2_subdev_call_state_try() with ifdefs, which would not use any state
macros and would always pass NULL as the state. But having two version
of a macro/function is always more confusing than having just one, so I
went this way.
So, this fixes the v4l2_subdev_call_state_active() macro. But we also
have v4l2_subdev_call_state_try(). It would be possible to fix that
macro by additionally creating "no-op" variants of the state alloc and
free functions. However, v4l2_subdev_call_state_try() is only used by a
single driver (stm32-dcmi), which selects MC, and the macro is supposed
to be removed as soon as the users have been converted away from the
macro. Thus I have not touched the state alloc/free functions, and I
think it makes sense to keep alloc/free functions available only if
there's actually something that can be allocated or freed.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/20231208-v4l2-state-mc-fix-v1-1-a0c8162557c6@ideasonboard.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Diffstat (limited to 'drivers/media/i2c/et8ek8/et8ek8_driver.c')
0 files changed, 0 insertions, 0 deletions