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

Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_atomic_helper.c | 165 +++++++++++++++++++++++++++++++++++- drivers/gpu/drm/drm_crtc_helper.c | 6 ++ include/drm/drm_atomic_helper.h | 6 ++ 3 files changed, 176 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 3232f4b838e4..31823dc8a406 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1742,6 +1742,164 @@ backoff: EXPORT_SYMBOL(drm_atomic_helper_set_config);

/** + * 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_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 = 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. + * + * 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); + drm_modeset_lock_all_ctx(dev, &ctx); + + 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_unlock_all_ctx(dev, &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 * @property: DRM property @@ -2354,7 +2512,9 @@ 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 @@ -2366,6 +2526,9 @@ 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 ef534758a02c..08620a25fe06 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 1547eb43c14a..98ffcb231079 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -75,6 +75,12 @@ 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_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);

On Tue, Sep 08, 2015 at 03:00:45PM +0200, Thierry Reding wrote:

From: Thierry Reding treding@nvidia.com

This function can be used to duplicate an atomic state object. This is useful for example to implement suspend/resume, where the state before suspend can be saved and restored upon resume.

v2: move locking to caller, be more explicit about prerequisites v3: explicitly pass lock acquisition context, improve kerneldoc

Signed-off-by: Thierry Reding treding@nvidia.com

Applied to drm-misc with 2 tiny spelling fixes in the kerneldoc.

Thanks, Daniel

---

drivers/gpu/drm/drm_atomic_helper.c | 78 +++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic_helper.h | 3 ++ 2 files changed, 81 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 634aa617811b..3232f4b838e4 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -2349,6 +2349,84 @@ drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector) EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);

/**

• • drm_atomic_helper_duplicate_state - duplicate an atomic state object
• • @dev: DRM device
• • @ctx: lock acquisition context
• • Makes a copy of the current atomic state by looping over all objects and
• • duplicating their respective states.
• • 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
• • or erroneous behaviour.
• • 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:
• • A pointer to the copy of the atomic state object on success or an
• • ERR_PTR()-encoded error code on failure.
• */

+struct drm_atomic_state * +drm_atomic_helper_duplicate_state(struct drm_device *dev,

• 		  struct drm_modeset_acquire_ctx *ctx)
  

+{

• struct drm_atomic_state *state;
• struct drm_connector *conn;
• struct drm_plane *plane;
• struct drm_crtc *crtc;
• int err = 0;
• state = drm_atomic_state_alloc(dev);
• if (!state)

• return ERR_PTR(-ENOMEM);
  

• state->acquire_ctx = ctx;
• drm_for_each_crtc(crtc, dev) {

• struct drm_crtc_state *crtc_state;
  

• crtc_state = drm_atomic_get_crtc_state(state, crtc);
  

• if (IS_ERR(crtc_state)) {
  

• 	err = PTR_ERR(crtc_state);
  

• 	goto free;
  

• }
  

• }
• drm_for_each_plane(plane, dev) {

• struct drm_plane_state *plane_state;
  

• plane_state = drm_atomic_get_plane_state(state, plane);
  

• if (IS_ERR(plane_state)) {
  

• 	err = PTR_ERR(plane_state);
  

• 	goto free;
  

• }
  

• }
• drm_for_each_connector(conn, dev) {

• struct drm_connector_state *conn_state;
  

• conn_state = drm_atomic_get_connector_state(state, conn);
  

• if (IS_ERR(conn_state)) {
  

• 	err = PTR_ERR(conn_state);
  

• 	goto free;
  

• }
  

• }
• /* clear the acquire context so that it isn't accidentally reused */
• state->acquire_ctx = NULL;

+free:

• if (err < 0) {

• drm_atomic_state_free(state);
  

• state = ERR_PTR(err);
  

• }
• return state;

+} +EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);

+/**

• __drm_atomic_helper_connector_destroy_state - release connector state
• @connector: connector object
• @state: connector state object to release

diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index 4ffe9dca07c4..1547eb43c14a 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -118,6 +118,9 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector, struct drm_connector_state *state); struct drm_connector_state * drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector); +struct drm_atomic_state * +drm_atomic_helper_duplicate_state(struct drm_device *dev,

• 		  struct drm_modeset_acquire_ctx *ctx);
  

void __drm_atomic_helper_connector_destroy_state(struct drm_connector *connector, struct drm_connector_state *state); -- 2.5.0