From: Thierry Reding treding@nvidia.com
Provide subsystem-level suspend and resume helpers that can be used to implement suspend/resume on atomic mode-setting enabled drivers.
v2: simplify locking, enhance kerneldoc comments
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_atomic_helper.c | 141 ++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic_helper.h | 5 ++ 2 files changed, 146 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 1f84df3b0a5d..0eb45a7a760e 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1751,6 +1751,147 @@ backoff: EXPORT_SYMBOL(drm_atomic_helper_set_config);
/** + * drm_atomic_helper_disable_all - disable all currently active outputs + * @dev: DRM device + * + * Loops through all connectors, finding those that aren't turned off and then + * turns them off by setting their DPMS mode to OFF and deactivating the CRTC + * that they are connected to. + * + * This is used for example in suspend/resume to disable all currently active + * functions when suspending. See drm_atomic_helper_suspend(). + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_atomic_helper_disable_all(struct drm_device *dev) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_connector_state *conn_state; + struct drm_atomic_state *state; + struct drm_connector *conn; + unsigned int i; + int err; + + state = drm_atomic_state_alloc(dev); + if (!state) + return -ENOMEM; + + state->acquire_ctx = config->acquire_ctx; + + drm_for_each_connector(conn, dev) { + struct drm_crtc *crtc = conn->state->crtc; + struct drm_crtc_state *crtc_state; + + if (!crtc || conn->dpms != DRM_MODE_DPMS_ON) + continue; + + crtc_state = drm_atomic_get_crtc_state(state, crtc); + if (IS_ERR(crtc_state)) { + err = PTR_ERR(crtc_state); + goto free; + } + + err = drm_atomic_add_affected_connectors(state, crtc); + if (err < 0) + goto free; + + conn->dpms = DRM_MODE_DPMS_OFF; + crtc_state->active = false; + } + + err = drm_atomic_commit(state); + if (err < 0) { + /* restore DPMS mode */ + for_each_connector_in_state(state, conn, conn_state, i) + conn->dpms = DRM_MODE_DPMS_ON; + + goto free; + } + +free: + if (err < 0) + drm_atomic_state_free(state); + + return err; +} +EXPORT_SYMBOL(drm_atomic_helper_disable_all); + +/** + * drm_atomic_helper_suspend - subsystem-level suspend helper + * @dev: DRM device + * + * Duplicates the current atomic state, disables all active outputs and then + * returns a pointer to the original atomic state to the caller. Drivers can + * pass this pointer to the drm_atomic_helper_resume() helper upon resume to + * restore the output configuration that was active at the time the system + * entered suspend. + * + * Note that it is potentially unsafe to use this. The atomic state object + * returned by this function is assumed to be persistent. Drivers must ensure + * that this holds true. Before calling this function, drivers must make sure + * to suspend fbdev emulation so that nothing can be using the device. + * + * Returns: + * A pointer to a copy of the state before suspend on success or an ERR_PTR()- + * encoded error code on failure. Drivers should store the returned atomic + * state object and pass it to the drm_atomic_helper_resume() helper upon + * resume. + */ +struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev) +{ + struct drm_atomic_state *state; + int err; + + drm_modeset_lock_all(dev); + + state = drm_atomic_helper_duplicate_state(dev); + if (IS_ERR(state)) + goto unlock; + + err = drm_atomic_helper_disable_all(dev); + if (err < 0) { + drm_atomic_state_free(state); + state = ERR_PTR(err); + goto unlock; + } + +unlock: + drm_modeset_unlock_all(dev); + return state; +} +EXPORT_SYMBOL(drm_atomic_helper_suspend); + +/** + * drm_atomic_helper_resume - subsystem-level resume helper + * @dev: DRM device + * @state: atomic state to resume to + * + * Calls drm_mode_config_reset() to synchronize hardware and software states, + * grabs all modeset locks and commits the atomic state object. This can be + * used in conjunction with the drm_atomic_helper_suspend() helper to + * implement suspend/resume for drivers that support atomic mode-setting. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_atomic_helper_resume(struct drm_device *dev, + struct drm_atomic_state *state) +{ + struct drm_mode_config *config = &dev->mode_config; + int err; + + drm_mode_config_reset(dev); + drm_modeset_lock_all(dev); + state->acquire_ctx = config->acquire_ctx; + err = drm_atomic_commit(state); + drm_modeset_unlock_all(dev); + + return err; +} +EXPORT_SYMBOL(drm_atomic_helper_resume); + +/** * drm_atomic_helper_crtc_set_property - helper for crtc properties * @crtc: DRM crtc * @property: DRM property diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index 5d27612997ce..080f131c9f2e 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -75,6 +75,11 @@ int drm_atomic_helper_update_plane(struct drm_plane *plane, int drm_atomic_helper_disable_plane(struct drm_plane *plane); int drm_atomic_helper_set_config(struct drm_mode_set *set);
+int drm_atomic_helper_disable_all(struct drm_device *dev); +struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev); +int drm_atomic_helper_resume(struct drm_device *dev, + struct drm_atomic_state *state); + int drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc, struct drm_property *property, uint64_t val);