From: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> 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@xxxxxxxxx/ 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@xxxxxxxxxxxxxxxx> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Link: https://lore.kernel.org/r/20231208-v4l2-state-mc-fix-v1-1-a0c8162557c6@xxxxxxxxxxxxxxxx Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> --- include/media/v4l2-subdev.h | 166 ++++++++++++++++++------------------ 1 file changed, 83 insertions(+), 83 deletions(-) diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 8b08f6640dee..61024a74ce38 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -1311,89 +1311,6 @@ int __v4l2_subdev_init_finalize(struct v4l2_subdev *sd, const char *name, */ void v4l2_subdev_cleanup(struct v4l2_subdev *sd); -/** - * v4l2_subdev_lock_state() - Locks the subdev state - * @state: The subdevice state - * - * Locks the given subdev state. - * - * The state must be unlocked with v4l2_subdev_unlock_state() after use. - */ -static inline void v4l2_subdev_lock_state(struct v4l2_subdev_state *state) -{ - mutex_lock(state->lock); -} - -/** - * v4l2_subdev_unlock_state() - Unlocks the subdev state - * @state: The subdevice state - * - * Unlocks the given subdev state. - */ -static inline void v4l2_subdev_unlock_state(struct v4l2_subdev_state *state) -{ - mutex_unlock(state->lock); -} - -/** - * v4l2_subdev_get_unlocked_active_state() - Checks that the active subdev state - * is unlocked and returns it - * @sd: The subdevice - * - * Returns the active state for the subdevice, or NULL if the subdev does not - * support active state. If the state is not NULL, calls - * lockdep_assert_not_held() to issue a warning if the state is locked. - * - * This function is to be used e.g. when getting the active state for the sole - * purpose of passing it forward, without accessing the state fields. - */ -static inline struct v4l2_subdev_state * -v4l2_subdev_get_unlocked_active_state(struct v4l2_subdev *sd) -{ - if (sd->active_state) - lockdep_assert_not_held(sd->active_state->lock); - return sd->active_state; -} - -/** - * v4l2_subdev_get_locked_active_state() - Checks that the active subdev state - * is locked and returns it - * - * @sd: The subdevice - * - * Returns the active state for the subdevice, or NULL if the subdev does not - * support active state. If the state is not NULL, calls lockdep_assert_held() - * to issue a warning if the state is not locked. - * - * This function is to be used when the caller knows that the active state is - * already locked. - */ -static inline struct v4l2_subdev_state * -v4l2_subdev_get_locked_active_state(struct v4l2_subdev *sd) -{ - if (sd->active_state) - lockdep_assert_held(sd->active_state->lock); - return sd->active_state; -} - -/** - * v4l2_subdev_lock_and_get_active_state() - Locks and returns the active subdev - * state for the subdevice - * @sd: The subdevice - * - * Returns the locked active state for the subdevice, or NULL if the subdev - * does not support active state. - * - * The state must be unlocked with v4l2_subdev_unlock_state() after use. - */ -static inline struct v4l2_subdev_state * -v4l2_subdev_lock_and_get_active_state(struct v4l2_subdev *sd) -{ - if (sd->active_state) - v4l2_subdev_lock_state(sd->active_state); - return sd->active_state; -} - /* * A macro to generate the macro or function name for sub-devices state access * wrapper macros below. @@ -1738,6 +1655,89 @@ int v4l2_subdev_s_stream_helper(struct v4l2_subdev *sd, int enable); #endif /* CONFIG_MEDIA_CONTROLLER */ +/** + * v4l2_subdev_lock_state() - Locks the subdev state + * @state: The subdevice state + * + * Locks the given subdev state. + * + * The state must be unlocked with v4l2_subdev_unlock_state() after use. + */ +static inline void v4l2_subdev_lock_state(struct v4l2_subdev_state *state) +{ + mutex_lock(state->lock); +} + +/** + * v4l2_subdev_unlock_state() - Unlocks the subdev state + * @state: The subdevice state + * + * Unlocks the given subdev state. + */ +static inline void v4l2_subdev_unlock_state(struct v4l2_subdev_state *state) +{ + mutex_unlock(state->lock); +} + +/** + * v4l2_subdev_get_unlocked_active_state() - Checks that the active subdev state + * is unlocked and returns it + * @sd: The subdevice + * + * Returns the active state for the subdevice, or NULL if the subdev does not + * support active state. If the state is not NULL, calls + * lockdep_assert_not_held() to issue a warning if the state is locked. + * + * This function is to be used e.g. when getting the active state for the sole + * purpose of passing it forward, without accessing the state fields. + */ +static inline struct v4l2_subdev_state * +v4l2_subdev_get_unlocked_active_state(struct v4l2_subdev *sd) +{ + if (sd->active_state) + lockdep_assert_not_held(sd->active_state->lock); + return sd->active_state; +} + +/** + * v4l2_subdev_get_locked_active_state() - Checks that the active subdev state + * is locked and returns it + * + * @sd: The subdevice + * + * Returns the active state for the subdevice, or NULL if the subdev does not + * support active state. If the state is not NULL, calls lockdep_assert_held() + * to issue a warning if the state is not locked. + * + * This function is to be used when the caller knows that the active state is + * already locked. + */ +static inline struct v4l2_subdev_state * +v4l2_subdev_get_locked_active_state(struct v4l2_subdev *sd) +{ + if (sd->active_state) + lockdep_assert_held(sd->active_state->lock); + return sd->active_state; +} + +/** + * v4l2_subdev_lock_and_get_active_state() - Locks and returns the active subdev + * state for the subdevice + * @sd: The subdevice + * + * Returns the locked active state for the subdevice, or NULL if the subdev + * does not support active state. + * + * The state must be unlocked with v4l2_subdev_unlock_state() after use. + */ +static inline struct v4l2_subdev_state * +v4l2_subdev_lock_and_get_active_state(struct v4l2_subdev *sd) +{ + if (sd->active_state) + v4l2_subdev_lock_state(sd->active_state); + return sd->active_state; +} + /** * v4l2_subdev_init - initializes the sub-device struct * -- Regards, Laurent Pinchart
