There should be a mechanism for drivers to respond to flip_done timeouts. Since, as it stands it is possible for the display to stall indefinitely, necessitating a hard reset. So, introduce a new mechanism that tries various methods of recovery with increasing aggression, in the following order:
1. Force a full modeset (have the compositor reprogram the state from scratch). 2. As a last resort, have the driver attempt a vendor specific reset (which they can do by reading the return value of drm_atomic_helper_wait_for_flip_done()). Signed-off-by: Hamza Mahfooz <[email protected]> --- v2: new to the series v3: get rid of page_flip_timeout() and have drm_atomic_helper_wait_for_flip_done() return a error. --- drivers/gpu/drm/drm_atomic_helper.c | 45 +++++++++++++++++++++++++---- include/drm/drm_atomic_helper.h | 4 +-- include/drm/drm_device.h | 24 +++++++++++++++ 3 files changed, 66 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 5840e9cc6f66..6ae1234b9e20 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -42,6 +42,7 @@ #include <drm/drm_gem_atomic_helper.h> #include <drm/drm_panic.h> #include <drm/drm_print.h> +#include <drm/drm_probe_helper.h> #include <drm/drm_self_refresh_helper.h> #include <drm/drm_vblank.h> #include <drm/drm_writeback.h> @@ -1864,11 +1865,15 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks); * * This requires that drivers use the nonblocking commit tracking support * initialized using drm_atomic_helper_setup_commit(). + * + * Returns: + * -ETIMEDOUT to indicate that drivers can attempt a vendor reset, 0 otherwise. */ -void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev, - struct drm_atomic_state *state) +int drm_atomic_helper_wait_for_flip_done(struct drm_device *dev, + struct drm_atomic_state *state) { struct drm_crtc *crtc; + int ret = 0; int i; for (i = 0; i < dev->mode_config.num_crtc; i++) { @@ -1881,13 +1886,43 @@ void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev, continue; ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ); - if (ret == 0) - drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n", - crtc->base.id, crtc->name); + if (!ret) { + switch (dev->reset_phase) { + case DRM_KMS_RESET_NONE: + drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n", + crtc->base.id, crtc->name); + dev->reset_phase = DRM_KMS_RESET_FORCE_MODESET; + drm_kms_helper_hotplug_event(dev); + break; + case DRM_KMS_RESET_FORCE_MODESET: + drm_err(dev, "[CRTC:%d:%s] force full modeset failed\n", + crtc->base.id, crtc->name); + dev->reset_phase = DRM_KMS_RESET_VENDOR; + ret = -ETIMEDOUT; + break; + case DRM_KMS_RESET_VENDOR: + drm_err(dev, "[CRTC:%d:%s] KMS recovery failed!\n", + crtc->base.id, crtc->name); + dev->reset_phase = DRM_KMS_RESET_GIVE_UP; + break; + default: + break; + } + + goto exit; + } + } + + if (dev->reset_phase) { + drm_info(dev, "KMS recovery succeeded!\n"); + dev->reset_phase = DRM_KMS_RESET_NONE; } +exit: if (state->fake_commit) complete_all(&state->fake_commit->flip_done); + + return ret; } EXPORT_SYMBOL(drm_atomic_helper_wait_for_flip_done); diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index 53382fe93537..298c8dff3993 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -79,8 +79,8 @@ int drm_atomic_helper_wait_for_fences(struct drm_device *dev, void drm_atomic_helper_wait_for_vblanks(struct drm_device *dev, struct drm_atomic_state *old_state); -void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev, - struct drm_atomic_state *old_state); +int drm_atomic_helper_wait_for_flip_done(struct drm_device *dev, + struct drm_atomic_state *old_state); void drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev, diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index bc78fb77cc27..1244d7527e7b 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -66,6 +66,23 @@ enum switch_power_state { DRM_SWITCH_POWER_DYNAMIC_OFF = 3, }; +/** + * enum drm_kms_reset_phase - reset phase of drm device + */ +enum drm_kms_reset_phase { + /** @DRM_KMS_RESET_NONE: Not currently attempting recovery */ + DRM_KMS_RESET_NONE, + + /** @DRM_KMS_RESET_FORCE_MODESET: Force a full modeset */ + DRM_KMS_RESET_FORCE_MODESET, + + /** @DRM_KMS_RESET_VENDOR: Attempt a vendor reset */ + DRM_KMS_RESET_VENDOR, + + /** @DRM_KMS_RESET_GIVE_UP: All recovery methods failed */ + DRM_KMS_RESET_GIVE_UP, +}; + /** * struct drm_device - DRM device structure * @@ -375,6 +392,13 @@ struct drm_device { * Root directory for debugfs files. */ struct dentry *debugfs_root; + + /** + * @reset_phase: + * + * Reset phase that the device is in. + */ + enum drm_kms_reset_phase reset_phase; }; void drm_dev_set_dma_dev(struct drm_device *dev, struct device *dma_dev); -- 2.53.0
