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Commit 14942760 authored by Thierry Reding's avatar Thierry Reding Committed by Daniel Vetter
Browse files

drm/atomic-helper: Implement subsystem-level suspend/resume 



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)
v5: handle potential EDEADLK from drm_atomic_helper_duplicate_state()
    and drm_atomic_helper_disable_all() (Daniel Vetter)

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449075005-13937-2-git-send-email-thierry.reding@gmail.com


Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 06eaae46

drivers/gpu/drm/drm_atomic_helper.c

+161 −1
Original line number Diff line number Diff line
@@ -1860,6 +1860,161 @@ int __drm_atomic_helper_set_config(struct drm_mode_set *set, 
	return 0;

}



/**

 * 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) {

		state = ERR_PTR(err);

		goto unlock;

	}



	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:

	if (PTR_ERR(state) == -EDEADLK) {

		drm_modeset_backoff(&ctx);

		goto retry;

	}



	drm_modeset_drop_locks(&ctx);

	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
@@ -2472,7 +2627,9 @@ 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
@@ -2484,6 +2641,9 @@ 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,

drivers/gpu/drm/drm_crtc_helper.c

+6 −0
Original line number Diff line number Diff line
@@ -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)

{

include/drm/drm_atomic_helper.h

+6 −0
Original line number Diff line number Diff line
@@ -83,6 +83,12 @@ 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);