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). 3. As a last resort, have the driver attempt a vendor specific reset (assuming it provides an implementation to drm_crtc_funcs.page_flip_timeout()). Signed-off-by: Hamza Mahfooz <[email protected]> --- v2: new to the series --- drivers/gpu/drm/drm_atomic_helper.c | 36 ++++++++++++++++++++++++++--- include/drm/drm_crtc.h | 9 ++++++++ include/drm/drm_device.h | 24 +++++++++++++++++++ 3 files changed, 66 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 5840e9cc6f66..f46d68418e32 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> @@ -1881,11 +1882,40 @@ 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; + if (crtc->funcs->page_flip_timeout) + crtc->funcs->page_flip_timeout(crtc); + 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); } diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 66278ffeebd6..45dc5a76e915 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -609,6 +609,15 @@ struct drm_crtc_funcs { uint32_t flags, uint32_t target, struct drm_modeset_acquire_ctx *ctx); + /** + * @page_flip_timeout: + * + * This optional hook is called if &drm_crtc_commit.flip_done times out, + * and can be used by drivers to attempt to recover from a page flip + * timeout. + */ + void (*page_flip_timeout)(struct drm_crtc *crtc); + /** * @set_property: * 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); -- 2.52.0
