From b09f9670b130380ebace4ce378ec04cb7d042871 Mon Sep 17 00:00:00 2001 From: Daniele Ceraolo Spurio Date: Thu, 23 Feb 2023 09:21:19 -0800 Subject: [PATCH] drm/i915/gsc: flush the GSC worker before wedging on unload If we unload the driver and wedge before the GSC worker is complete, the worker will hit an error on its submission to the GSC engine and then exit. This is hard to hit for a user, but it is reproducible with skipping selftests. The error is handled gracefully by the worker, so there are no functional issues, but we still end up with an error message in dmesg, which is something we want to avoid as this is a supported scenario. We could modify the worker to better handle a wedging occurring during its execution, but that gets complicated for a couple of reasons: - We do want the error on runtime wedging, because there are implications for subsystems outside of GT (i.e., PXP, HDCP), it's only the error on driver unload that we want to silence. - The worker is responsible for multiple submissions (GSC FW load, HuC auth, SW proxy), so all of those will have to be adapted to handle the wedged_on_fini scenario. Therefore, it's much simpler to just wait for the worker to be done before wedging on driver removal, also considering that the worker will likely already be idle in the great majority of non-selftest scenarios. Signed-off-by: Daniele Ceraolo Spurio Cc: Alan Previn Reviewed-by: Alan Previn Link: https://patchwork.freedesktop.org/patch/msgid/20230223172120.3304293-2-daniele.ceraolospurio@intel.com --- drivers/gpu/drm/i915/gt/intel_gt.c | 23 +++++++++++++++++++++++ drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c | 2 +- drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.h | 1 + drivers/gpu/drm/i915/gt/uc/intel_uc.c | 2 +- 4 files changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index f7f2717..89ccb95 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -785,6 +785,29 @@ void intel_gt_driver_unregister(struct intel_gt *gt) intel_gsc_fini(>->gsc); /* + * If we unload the driver and wedge before the GSC worker is complete, + * the worker will hit an error on its submission to the GSC engine and + * then exit. This is hard to hit for a user, but it is reproducible + * with skipping selftests. The error is handled gracefully by the + * worker, so there are no functional issues, but we still end up with + * an error message in dmesg, which is something we want to avoid as + * this is a supported scenario. We could modify the worker to better + * handle a wedging occurring during its execution, but that gets + * complicated for a couple of reasons: + * - We do want the error on runtime wedging, because there are + * implications for subsystems outside of GT (i.e., PXP, HDCP), it's + * only the error on driver unload that we want to silence. + * - The worker is responsible for multiple submissions (GSC FW load, + * HuC auth, SW proxy), so all of those will have to be adapted to + * handle the wedged_on_fini scenario. + * Therefore, it's much simpler to just wait for the worker to be done + * before wedging on driver removal, also considering that the worker + * will likely already be idle in the great majority of non-selftest + * scenarios. + */ + intel_gsc_uc_flush_work(>->uc.gsc); + + /* * Upon unregistering the device to prevent any new users, cancel * all in-flight requests so that we can quickly unbind the active * resources. diff --git a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c index 8afd42c..92e1571 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c @@ -116,7 +116,7 @@ void intel_gsc_uc_fini(struct intel_gsc_uc *gsc) intel_uc_fw_fini(&gsc->fw); } -void intel_gsc_uc_suspend(struct intel_gsc_uc *gsc) +void intel_gsc_uc_flush_work(struct intel_gsc_uc *gsc) { if (!intel_uc_fw_is_loadable(&gsc->fw)) return; diff --git a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.h b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.h index 03fd0a8..c8b0253 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.h @@ -26,6 +26,7 @@ void intel_gsc_uc_init_early(struct intel_gsc_uc *gsc); int intel_gsc_uc_init(struct intel_gsc_uc *gsc); void intel_gsc_uc_fini(struct intel_gsc_uc *gsc); void intel_gsc_uc_suspend(struct intel_gsc_uc *gsc); +void intel_gsc_uc_flush_work(struct intel_gsc_uc *gsc); void intel_gsc_uc_load_start(struct intel_gsc_uc *gsc); static inline bool intel_gsc_uc_is_supported(struct intel_gsc_uc *gsc) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c index 6648691..5fa5c09 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c @@ -672,7 +672,7 @@ void intel_uc_suspend(struct intel_uc *uc) int err; /* flush the GSC worker */ - intel_gsc_uc_suspend(&uc->gsc); + intel_gsc_uc_flush_work(&uc->gsc); if (!intel_guc_is_ready(guc)) { guc->interrupts.enabled = false; -- 2.7.4