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 v3: pass lock acquisition context by parameter, improve kerneldoc v4: - remove redundant code (already provided by atomic helpers) (Maarten Lankhorst) - move backoff dance from drm_modeset_lock_all_ctx() into suspend helper (Daniel Vetter)
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_atomic_helper.c | 163 +++++++++++++++++++++++++++++++++++- drivers/gpu/drm/drm_crtc_helper.c | 6 ++ include/drm/drm_atomic_helper.h | 6 ++ 3 files changed, 174 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 3731a26979bc..1b51722b2a00 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1818,6 +1818,162 @@ commit: }
/** + * drm_atomic_helper_disable_all - disable all currently active outputs + * @dev: DRM device + * @ctx: lock acquisition context + * + * 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. + * + * Note that if callers haven't already acquired all modeset locks this might + * return -EDEADLK, which must be handled by calling drm_modeset_backoff(). + * + * Returns: + * 0 on success or a negative error code on failure. + * + * See also: + * drm_atomic_helper_suspend(), drm_atomic_helper_resume() + */ +int drm_atomic_helper_disable_all(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_atomic_state *state; + struct drm_connector *conn; + int err; + + state = drm_atomic_state_alloc(dev); + if (!state) + return -ENOMEM; + + state->acquire_ctx = 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; + } + + crtc_state->active = false; + } + + err = drm_atomic_commit(state); + +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. + * + * See also: + * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(), + * drm_atomic_helper_resume() + */ +struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev) +{ + struct drm_modeset_acquire_ctx ctx; + struct drm_atomic_state *state; + int err; + + drm_modeset_acquire_init(&ctx, 0); + +retry: + err = drm_modeset_lock_all_ctx(dev, &ctx); + if (err < 0) { + if (err == -EDEADLK) { + drm_modeset_backoff(&ctx); + goto retry; + } + + state = ERR_PTR(err); + goto fini; + } + + state = drm_atomic_helper_duplicate_state(dev, &ctx); + if (IS_ERR(state)) + goto unlock; + + err = drm_atomic_helper_disable_all(dev, &ctx); + if (err < 0) { + drm_atomic_state_free(state); + state = ERR_PTR(err); + goto unlock; + } + +unlock: + drm_modeset_drop_locks(&ctx); +fini: + drm_modeset_acquire_fini(&ctx); + 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. + * + * See also: + * drm_atomic_helper_suspend() + */ +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 @@ -2429,7 +2585,9 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state); * @ctx: lock acquisition context * * Makes a copy of the current atomic state by looping over all objects and - * duplicating their respective states. + * duplicating their respective states. This is used for example by suspend/ + * resume support code to save the state prior to suspend such that it can + * be restored upon resume. * * Note that this treats atomic state as persistent between save and restore. * Drivers must make sure that this is possible and won't result in confusion @@ -2441,6 +2599,9 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state); * Returns: * A pointer to the copy of the atomic state object on success or an * ERR_PTR()-encoded error code on failure. + * + * See also: + * drm_atomic_helper_suspend(), drm_atomic_helper_resume() */ struct drm_atomic_state * drm_atomic_helper_duplicate_state(struct drm_device *dev, diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 6b4cf25fed12..10d0989db273 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -855,6 +855,12 @@ EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct); * due to slight differences in allocating shared resources when the * configuration is restored in a different order than when userspace set it up) * need to use their own restore logic. + * + * This function is deprecated. New drivers should implement atomic mode- + * setting and use the atomic suspend/resume helpers. + * + * See also: + * drm_atomic_helper_suspend(), drm_atomic_helper_resume() */ void drm_helper_resume_force_mode(struct drm_device *dev) { diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index 8cba54a2a0a0..8045cdea8cc9 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -81,6 +81,12 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set); int __drm_atomic_helper_set_config(struct drm_mode_set *set, struct drm_atomic_state *state);
+int drm_atomic_helper_disable_all(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx); +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);