The upcoming DRM_MODE_ATOMIC_RESET flag will need to create an atomic commit that brings the entire device back to a pristine state, as if no configuration had ever been applied.
Create drm_atomic_commit_fill_with_defaults() which iterates over all CRTCs, planes, connectors, and color operations in the device and inserts a fresh default state for each one into the commit. This uses the atomic_create_state() hooks rather than atomic_duplicate_state(), since atomic_create_state() provides exactly this pristine state on a per-object basis. Signed-off-by: Maxime Ripard <[email protected]> --- drivers/gpu/drm/drm_atomic.c | 285 +++++++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_ioctl.c | 1 + include/drm/drm_atomic.h | 2 + 3 files changed, 288 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 7a77051096c9..6bc0d6339f14 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1650,4 +1650,289 @@ bool drm_atomic_implements_create_state(struct drm_device *dev) EXPORT_SYMBOL(drm_atomic_implements_create_state); +/* + * Returns true if the colorop state @new differs from the colorop state + * @old. + */ +static bool drm_atomic_colorop_state_changed(const struct drm_colorop_state *old, + const struct drm_colorop_state *new) +{ + return old->bypass != new->bypass || + old->curve_1d_type != new->curve_1d_type || + old->multiplier != new->multiplier || + old->data != new->data || + old->lut1d_interpolation != new->lut1d_interpolation || + old->lut3d_interpolation != new->lut3d_interpolation || + old->fixed_matrix_type != new->fixed_matrix_type; +} + +/** + * drm_atomic_commit_fill_with_defaults - populate a commit with pristine states + * @file_priv: DRM file the reset was requested from, or NULL + * @commit: atomic commit to fill + * + * Iterate over all CRTCs, planes, connectors, and color operations in + * the device and insert a freshly created default state for each one + * into @commit. The states are created through the atomic_create_state() + * hooks, producing the same initial state the driver starts with rather + * than a copy of the current hardware state. + * + * If @file_priv is a lessee, only the CRTCs, planes and connectors part + * of its lease are reset, and the other ones are left untouched. + * @file_priv is optional: if NULL, it is considered to not hold any + * lease, and all objects are reset. + * + * The objects that are bound to the objects being reset are still added + * to the commit, with their current state: the CRTC a reset plane or + * connector is bound to, and the connectors bound to a reset CRTC. The + * atomic helpers require them to be part of the commit to update the + * CRTC state and the routing, and they would dereference a NULL state + * otherwise. + * + * In the default state, all objects are disabled: CRTCs are inactive, + * planes are disabled, and connectors are unbound. Driver-specific + * properties such as color pipeline settings or max_bpc may carry + * non-zero defaults appropriate for basic display output. + * + * The CRTC and plane states in the commit carry color_mgmt_changed set + * when the reset changes the color management properties compared to the + * current state, so that drivers reprogram the color management + * hardware. + * + * The connector states keep the encoder currently in use in their + * best_encoder field, like a duplicated state would, so that the atomic + * helpers can detect the commits that don't change the connector + * routing. + * + * This is meant to be used with the %DRM_MODE_ATOMIC_RESET flag, which + * needs to bring the device back to a known baseline before applying + * userspace property changes on top. + * + * Returns: + * 0 on success, or a negative error code on failure. + */ +int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv, + struct drm_atomic_commit *commit) +{ + struct drm_device *dev = commit->dev; + struct drm_mode_config *config = &dev->mode_config; + struct drm_crtc *crtc; + struct drm_plane *plane; + struct drm_connector *connector; + struct drm_connector_list_iter conn_iter; + struct drm_colorop *colorop; + int ret; + + drm_WARN_ON(dev, !commit->acquire_ctx); + + /* + * Private objects are ignored because none have userspace + * properties we might want to reset. atomic_check + * implementations will derive or infer their private obj state + * from the state that will end up being committed anyway. + * + * The CRTCs are handled before the planes and connectors so that, + * when those pull the CRTC they are currently bound to into the + * commit, a leased CRTC is already there with its pristine state + * while an unleased one gets duplicated and keeps its current + * state. + */ + drm_for_each_crtc(crtc, dev) { + struct drm_crtc_state *crtc_state; + + if (!drm_lease_held(file_priv, crtc->base.id)) + continue; + + ret = drm_modeset_lock(&crtc->mutex, commit->acquire_ctx); + if (ret) + return ret; + + crtc_state = crtc->funcs->atomic_create_state(crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + /* + * The userspace property handlers only set + * color_mgmt_changed when a property write changes the + * value stored in the new state. Since the pristine states + * we create here are already set to their default values, + * restoring those defaults wouldn't set the flag, and + * neither would leaving the properties untouched, even + * though the commit clears whatever LUT or CTM is + * currently programmed. Compare with the current state + * so that the drivers reprogram the color management + * hardware. + */ + crtc_state->color_mgmt_changed = + crtc->state->degamma_lut != crtc_state->degamma_lut || + crtc->state->ctm != crtc_state->ctm || + crtc->state->gamma_lut != crtc_state->gamma_lut; + + drm_atomic_commit_set_crtc_state(commit, crtc, crtc_state); + } + + drm_for_each_plane(plane, dev) { + struct drm_plane_state *plane_state; + + if (!drm_lease_held(file_priv, plane->base.id)) + continue; + + ret = drm_modeset_lock(&plane->mutex, commit->acquire_ctx); + if (ret) + return ret; + + /* + * Make sure the CRTC the plane is currently enabled on is + * part of the commit, like drm_atomic_set_crtc_for_plane() + * does when userspace disables a plane. The atomic helpers + * need the CRTC state to update planes_changed and track + * the commit, and would dereference a NULL CRTC state + * otherwise. + */ + if (plane->state->crtc) { + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(commit, + plane->state->crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + } + + plane_state = plane->funcs->atomic_create_state(plane); + if (IS_ERR(plane_state)) + return PTR_ERR(plane_state); + + /* + * Same thing for the planes: report a color pipeline change + * compared to the current state. + */ + plane_state->color_mgmt_changed = + plane->state->color_pipeline != plane_state->color_pipeline; + + drm_atomic_commit_set_plane_state(commit, plane, plane_state); + } + + drm_for_each_colorop(colorop, dev) { + struct drm_plane_state *plane_state; + struct drm_colorop_state *colorop_state; + + if (!drm_lease_held(file_priv, colorop->plane->base.id)) + continue; + + ret = drm_modeset_lock(&colorop->plane->mutex, commit->acquire_ctx); + if (ret) + return ret; + + colorop_state = drm_atomic_helper_colorop_create_state(colorop); + if (IS_ERR(colorop_state)) + return PTR_ERR(colorop_state); + + drm_atomic_commit_set_colorop_state(commit, colorop, colorop_state); + + /* + * Report the colorop state changes on their plane state, + * like drm_atomic_set_property() does when userspace + * changes a colorop property. + */ + if (drm_atomic_colorop_state_changed(colorop->state, colorop_state)) { + plane_state = drm_atomic_get_new_plane_state(commit, + colorop->plane); + if (plane_state) + plane_state->color_mgmt_changed = true; + } + } + + ret = drm_modeset_lock(&config->connection_mutex, commit->acquire_ctx); + if (ret) + return ret; + + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector, &conn_iter) { + struct drm_connector_state *connector_state; + struct drm_crtc_state *crtc_state; + + if (!drm_lease_held(file_priv, connector->base.id)) { + /* + * The connector isn't part of the lease so it keeps + * its current state, but if it is bound to a CRTC + * that is part of the commit, pull it in like + * drm_atomic_add_affected_connectors() would do on a + * regular commit, so that its routing and encoder + * are properly handled. + */ + if (!connector->state->crtc) + continue; + + if (!drm_atomic_get_new_crtc_state(commit, + connector->state->crtc)) + continue; + + connector_state = drm_atomic_get_connector_state(commit, + connector); + if (IS_ERR(connector_state)) { + drm_connector_list_iter_end(&conn_iter); + return PTR_ERR(connector_state); + } + + continue; + } + + /* + * drm_atomic_implements_create_state() already checked + * this, but connectors can be hotplugged between that + * lockless check and the iteration here. + */ + if (!connector->funcs->atomic_create_state) { + drm_connector_list_iter_end(&conn_iter); + return -EOPNOTSUPP; + } + + connector_state = connector->funcs->atomic_create_state(connector); + if (IS_ERR(connector_state)) { + drm_connector_list_iter_end(&conn_iter); + ret = PTR_ERR(connector_state); + return ret; + } + + /* + * best_encoder is a routing information maintained by the + * atomic helpers rather than a userspace property, and it + * is only carried over to a new state when that state is a + * duplicate of the current one. Since + * update_connector_routing() uses it to detect the commits + * that keep the connector routing unchanged, let's carry + * the encoder currently in use over so that a reset on + * which userspace re-applies the exact same configuration + * doesn't require a modeset. + */ + connector_state->best_encoder = connector->state->best_encoder; + + ret = drm_atomic_commit_set_connector_state(commit, connector, connector_state); + if (ret) { + connector->funcs->atomic_destroy_state(connector, connector_state); + drm_connector_list_iter_end(&conn_iter); + return ret; + } + + /* + * Make sure the CRTC the connector is currently bound to + * is part of the commit, like drm_atomic_get_connector_state() + * does, so that the atomic helpers can update the CRTC + * state and the connector routing. + */ + if (connector->state->crtc) { + crtc_state = drm_atomic_get_crtc_state(commit, + connector->state->crtc); + if (IS_ERR(crtc_state)) { + drm_connector_list_iter_end(&conn_iter); + return PTR_ERR(crtc_state); + } + } + } + drm_connector_list_iter_end(&conn_iter); + + return 0; +} +EXPORT_SYMBOL(drm_atomic_commit_fill_with_defaults); + /** * drm_atomic_add_encoder_bridges - add bridges attached to an encoder diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 9039a39c4324..0dbf04d4aa9e 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -34,4 +34,5 @@ #include <linux/uaccess.h> +#include <drm/drm_atomic.h> #include <drm/drm_auth.h> #include <drm/drm_crtc.h> diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index 72c3d420f40c..cac74d43a34d 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -704,4 +704,6 @@ void drm_atomic_commit_clear(struct drm_atomic_commit *state); bool drm_atomic_implements_create_state(struct drm_device *dev); +int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv, + struct drm_atomic_commit *commit); /** -- 2.55.0
