From 620eec75f35ce470cb59410b2ed91ad750b867a2 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 9 Jul 2018 10:40:15 +0200 Subject: [PATCH] drm/doc: use inline kerneldoc style for drm_crtc_state Lots of added text here since I think the various control flow bits are worth explaining a bit better. v2: Fix conflict with Boris' no_vblank addition. Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20180709084016.23750-15-daniel.vetter@ffwll.ch --- include/drm/drm_crtc.h | 110 ++++++++++++++++++++++++++++++++--------- 1 file changed, 86 insertions(+), 24 deletions(-) diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 7fe06ad6e5f0..92e7fc7f05a4 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -77,21 +77,6 @@ struct drm_plane_helper_funcs; /** * struct drm_crtc_state - mutable CRTC state - * @crtc: backpointer to the CRTC - * @enable: whether the CRTC should be enabled, gates all other state - * @active: whether the CRTC is actively displaying (used for DPMS) - * @planes_changed: planes on this crtc are updated - * @mode_changed: @mode or @enable has been changed - * @active_changed: @active has been toggled. - * @connectors_changed: connectors to this crtc have been updated - * @zpos_changed: zpos values of planes on this crtc have been updated - * @color_mgmt_changed: color management properties have changed (degamma or - * gamma LUT or CSC matrix) - * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes - * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors - * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders - * @mode_blob: &drm_property_blob for @mode - * @state: backpointer to global drm_atomic_state * * Note that the distinction between @enable and @active is rather subtile: * Flipping @active while @enable is set without changing anything else may @@ -102,21 +87,86 @@ struct drm_plane_helper_funcs; * * The three booleans active_changed, connectors_changed and mode_changed are * intended to indicate whether a full modeset is needed, rather than strictly - * describing what has changed in a commit. - * See also: drm_atomic_crtc_needs_modeset() + * describing what has changed in a commit. See also: + * drm_atomic_crtc_needs_modeset() + * + * WARNING: Transitional helpers (like drm_helper_crtc_mode_set() or + * drm_helper_crtc_mode_set_base()) do not maintain many of the derived control + * state like @plane_mask so drivers not converted over to atomic helpers should + * not rely on these being accurate! */ struct drm_crtc_state { + /** @crtc: backpointer to the CRTC */ struct drm_crtc *crtc; + /** + * @enable: Whether the CRTC should be enabled, gates all other state. + * This controls reservations of shared resources. Actual hardware state + * is controlled by @active. + */ bool enable; + + /** + * @active: Whether the CRTC is actively displaying (used for DPMS). + * Implies that @enable is set. The driver must not release any shared + * resources if @active is set to false but @enable still true, because + * userspace expects that a DPMS ON always succeeds. + * + * Hence drivers must not consult @active in their various + * &drm_mode_config_funcs.atomic_check callback to reject an atomic + * commit. They can consult it to aid in the computation of derived + * hardware state, since even in the DPMS OFF state the display hardware + * should be as much powered down as when the CRTC is completely + * disabled through setting @enable to false. + */ bool active; - /* computed state bits used by helpers and drivers */ + /** + * @planes_changed: Planes on this crtc are updated. Used by the atomic + * helpers and drivers to steer the atomic commit control flow. + */ bool planes_changed : 1; + + /** + * @mode_changed: @mode or @enable has been changed. Used by the atomic + * helpers and drivers to steer the atomic commit control flow. See also + * drm_atomic_crtc_needs_modeset(). + * + * Drivers are supposed to set this for any CRTC state changes that + * require a full modeset. They can also reset it to false if e.g. a + * @mode change can be done without a full modeset by only changing + * scaler settings. + */ bool mode_changed : 1; + + /** + * @active_changed: @active has been toggled. Used by the atomic + * helpers and drivers to steer the atomic commit control flow. See also + * drm_atomic_crtc_needs_modeset(). + */ bool active_changed : 1; + + /** + * @connectors_changed: Connectors to this crtc have been updated, + * either in their state or routing. Used by the atomic + * helpers and drivers to steer the atomic commit control flow. See also + * drm_atomic_crtc_needs_modeset(). + * + * Drivers are supposed to set this as-needed from their own atomic + * check code, e.g. from &drm_encoder_helper_funcs.atomic_check + */ bool connectors_changed : 1; + /** + * @zpos_changed: zpos values of planes on this crtc have been updated. + * Used by the atomic helpers and drivers to steer the atomic commit + * control flow. + */ bool zpos_changed : 1; + /** + * @color_mgmt_changed: Color management properties have changed + * (@gamma_lut, @degamma_lut or @ctm). Used by the atomic helpers and + * drivers to steer the atomic commit control flow. + */ bool color_mgmt_changed : 1; /** @@ -142,14 +192,22 @@ struct drm_crtc_state { */ bool no_vblank : 1; - /* attached planes bitmask: - * WARNING: transitional helpers do not maintain plane_mask so - * drivers not converted over to atomic helpers should not rely - * on plane_mask being accurate! + /** + * @plane_mask: Bitmask of drm_plane_mask(plane) of planes attached to + * this CRTC. */ u32 plane_mask; + /** + * @connector_mask: Bitmask of drm_connector_mask(connector) of + * connectors attached to this CRTC. + */ u32 connector_mask; + + /** + * @encoder_mask: Bitmask of drm_encoder_mask(encoder) of encoders + * attached to this CRTC. + */ u32 encoder_mask; /** @@ -159,7 +217,7 @@ struct drm_crtc_state { * differences between the mode requested by userspace in @mode and what * is actually programmed into the hardware. * - * For drivers using drm_bridge, this stores hardware display timings + * For drivers using &drm_bridge, this stores hardware display timings * used between the CRTC and the first bridge. For other drivers, the * meaning of the adjusted_mode field is purely driver implementation * defined information, and will usually be used to store the hardware @@ -184,7 +242,10 @@ struct drm_crtc_state { */ struct drm_display_mode mode; - /* blob property to expose current mode to atomic userspace */ + /** + * @mode_blob: &drm_property_blob for @mode, for exposing the mode to + * atomic userspace. + */ struct drm_property_blob *mode_blob; /** @@ -288,6 +349,7 @@ struct drm_crtc_state { */ struct drm_crtc_commit *commit; + /** @state: backpointer to global drm_atomic_state */ struct drm_atomic_state *state; };