On Wed, Aug 12, 2015 at 04:37:29PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> ---
> 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().
I think an analog paragraph should be added to duplicate_state(), maybe in
this patch?
> + *
> + * Returns:
> + * 0 on success or a negative error code on failure.
Please add the same caveat about locking like for duplicate_state here.
> + */
> +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;
Same comment about reusing the hidden acquire_ctx: Please don't and
instead make it an explicit paramter.
> +
> + 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.
I'd mention the two helpers explicitly so that they all get linked up here
in the kerneldoc (i.e. duplicate_state() and disable_all()).
lgtm otherwise.
-Daniel
> + *
> + * 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);
> --
> 2.4.5
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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