diff options
| -rw-r--r-- | include/drm/drm_modeset_helper_vtables.h | 210 |
1 files changed, 199 insertions, 11 deletions
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 56dadfe7a181..c77b7dcf343b 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -62,9 +62,6 @@ enum mode_set_atomic; * @load_lut: load color palette * @disable: disable CRTC when no longer in use * @enable: enable CRTC - * @atomic_check: check for validity of an atomic state - * @atomic_begin: begin atomic update - * @atomic_flush: flush atomic update * * The helper operations are called by the mid-layer CRTC helper. * @@ -108,11 +105,96 @@ struct drm_crtc_helper_funcs { void (*disable)(struct drm_crtc *crtc); void (*enable)(struct drm_crtc *crtc); - /* atomic helpers */ + /** + * @atomic_check: + * + * Drivers should check plane-update related CRTC constraints in this + * hook. They can also check mode related limitations but need to be + * aware of the calling order, since this hook is used by + * drm_atomic_helper_check_planes() whereas the preparations needed to + * check output routing and the display mode is done in + * drm_atomic_helper_check_modeset(). Therefore drivers that want to + * check output routing and display mode constraints in this callback + * must ensure that drm_atomic_helper_check_modeset() has been called + * beforehand. This is calling order used by the default helper + * implementation in drm_atomic_helper_check(). + * + * When using drm_atomic_helper_check_planes() CRTCs' ->atomic_check() + * hooks are called after the ones for planes, which allows drivers to + * assign shared resources requested by planes in the CRTC callback + * here. For more complicated dependencies the driver can call the provided + * check helpers multiple times until the computed state has a final + * configuration and everything has been checked. + * + * This function is also allowed to inspect any other object's state and + * can add more state objects to the atomic commit if needed. Care must + * be taken though to ensure that state check&compute functions for + * these added states are all called, and derived state in other objects + * all updated. Again the recommendation is to just call check helpers + * until a maximal configuration is reached. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + * + * NOTE: + * + * This function is called in the check phase of an atomic update. The + * driver is not allowed to change anything outside of the free-standing + * state objects passed-in or assembled in the overall &drm_atomic_state + * update tracking structure. + * + * RETURNS: + * + * 0 on success, -EINVAL if the state or the transition can't be + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an + * attempt to obtain another state object ran into a &drm_modeset_lock + * deadlock. + */ int (*atomic_check)(struct drm_crtc *crtc, struct drm_crtc_state *state); + + /** + * @atomic_begin: + * + * Drivers should prepare for an atomic update of multiple planes on + * a CRTC in this hook. Depending upon hardware this might be vblank + * evasion, blocking updates by setting bits or doing preparatory work + * for e.g. manual update display. + * + * This hook is called before any plane commit functions are called. + * + * Note that the power state of the display pipe when this function is + * called depends upon the exact helpers and calling sequence the driver + * has picked. See drm_atomic_commit_planes() for a discussion of the + * tradeoffs and variants of plane commit helpers. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + */ void (*atomic_begin)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); + /** + * @atomic_flush: + * + * Drivers should finalize an atomic update of multiple planes on + * a CRTC in this hook. Depending upon hardware this might include + * checking that vblank evasion was successful, unblocking updates by + * setting bits or setting the GO bit to flush out all updates. + * + * Simple hardware or hardware with special requirements can commit and + * flush out all updates for all planes from this hook and forgo all the + * other commit hooks for plane updates. + * + * This hook is called after any plane commit functions are called. + * + * Note that the power state of the display pipe when this function is + * called depends upon the exact helpers and calling sequence the driver + * has picked. See drm_atomic_commit_planes() for a discussion of the + * tradeoffs and variants of plane commit helpers. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + */ void (*atomic_flush)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); }; @@ -216,25 +298,131 @@ static inline void drm_connector_helper_add(struct drm_connector *connector, } /** - * struct drm_plane_helper_funcs - helper operations for CRTCs - * @prepare_fb: prepare a framebuffer for use by the plane - * @cleanup_fb: cleanup a framebuffer when it's no longer used by the plane - * @atomic_check: check that a given atomic state is valid and can be applied - * @atomic_update: apply an atomic state to the plane (mandatory) - * @atomic_disable: disable the plane + * struct drm_plane_helper_funcs - helper operations for planes * - * The helper operations are called by the mid-layer CRTC helper. + * These functions are used by the atomic helpers and by the transitional plane + * helpers. */ struct drm_plane_helper_funcs { + /** + * @prepare_fb: + * + * This hook is to prepare a framebuffer for scanout by e.g. pinning + * it's backing storage or relocating it into a contiguous block of + * VRAM. Other possible preparatory work includes flushing caches. + * + * This function must not block for outstanding rendering, since it is + * called in the context of the atomic IOCTL even for async commits to + * be able to return any errors to userspace. Instead the recommended + * way is to fill out the fence member of the passed-in + * &drm_plane_state. If the driver doesn't support native fences then + * equivalent functionality should be implemented through private + * members in the plane structure. + * + * The helpers will call @cleanup_fb with matching arguments for every + * successful call to this hook. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + * + * RETURNS: + * + * 0 on success or one of the following negative error codes allowed by + * the atomic_commit hook in &drm_mode_config_funcs. When using helpers + * this callback is the only one which can fail an atomic commit, + * everything else must complete successfully. + */ int (*prepare_fb)(struct drm_plane *plane, const struct drm_plane_state *new_state); + /** + * @cleanup_fb: + * + * This hook is called to clean up any resources allocated for the given + * framebuffer and plane configuration in @prepare_fb. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + */ void (*cleanup_fb)(struct drm_plane *plane, const struct drm_plane_state *old_state); + /** + * @atomic_check: + * + * Drivers should check plane specific constraints in this hook. + * + * When using drm_atomic_helper_check_planes() plane's ->atomic_check() + * hooks are called before the ones for CRTCs, which allows drivers to + * request shared resources that the CRTC controls here. For more + * complicated dependencies the driver can call the provided check helpers + * multiple times until the computed state has a final configuration and + * everything has been checked. + * + * This function is also allowed to inspect any other object's state and + * can add more state objects to the atomic commit if needed. Care must + * be taken though to ensure that state check&compute functions for + * these added states are all called, and derived state in other objects + * all updated. Again the recommendation is to just call check helpers + * until a maximal configuration is reached. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + * + * NOTE: + * + * This function is called in the check phase of an atomic update. The + * driver is not allowed to change anything outside of the free-standing + * state objects passed-in or assembled in the overall &drm_atomic_state + * update tracking structure. + * + * RETURNS: + * + * 0 on success, -EINVAL if the state or the transition can't be + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an + * attempt to obtain another state object ran into a &drm_modeset_lock + * deadlock. + */ int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state); + + /** + * @atomic_update: + * + * Drivers should use this function to update the plane state. This + * hook is called in-between the ->atomic_begin() and + * ->atomic_flush() of &drm_crtc_helper_funcs. + * + * Note that the power state of the display pipe when this function is + * called depends upon the exact helpers and calling sequence the driver + * has picked. See drm_atomic_commit_planes() for a discussion of the + * tradeoffs and variants of plane commit helpers. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + */ void (*atomic_update)(struct drm_plane *plane, struct drm_plane_state *old_state); + /** + * @atomic_disable: + * + * Drivers should use this function to unconditionally disable a plane. + * This hook is called in-between the ->atomic_begin() and + * ->atomic_flush() of &drm_crtc_helper_funcs. It is an alternative to + * @atomic_update, which will be called for disabling planes, too, if + * the @atomic_disable hook isn't implemented. + * + * This hook is also useful to disable planes in preparation of a modeset, + * by calling drm_atomic_helper_disable_planes_on_crtc() from the + * ->disable() hook in &drm_crtc_helper_funcs. + * + * Note that the power state of the display pipe when this function is + * called depends upon the exact helpers and calling sequence the driver + * has picked. See drm_atomic_commit_planes() for a discussion of the + * tradeoffs and variants of plane commit helpers. + * + * This callback is used by the atomic modeset helpers and by the + * transitional plane helpers, but it is optional. + */ void (*atomic_disable)(struct drm_plane *plane, struct drm_plane_state *old_state); }; |