This patch fixes a timing issue that causes a GPU hang when the system comes out of power saving.
During pm_resume, We are submitting batchbuffers before enabling Interrupts this is causing us to miss the context switch interrupt, and in consequence intel_execlists_handle_ctx_events is not triggered. This patch is based on a patch from Deepak S <deepa...@intel.com> from another platform. The patch fixes an issue introduced by: commit e7778be1eab918274f79603d7c17b3ec8be77386 drm/i915: Fix startup failure in LRC mode after recent init changes The above patch added a call to init_context() to fix an issue introduced by a previous patch. But, it then opened up a small timing window for the batches being added by the init_context (basically setting up the context) to complete before the interrupts have been turned on, thus hanging the GPU. BUG: https://bugs.freedesktop.org/show_bug.cgi?id=89600 Signed-off-by: Peter Antoine <peter.anto...@intel.com> --- drivers/gpu/drm/i915/i915_drv.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 6bb6c47..90b1309 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -734,6 +734,12 @@ static int i915_drm_resume(struct drm_device *dev) intel_init_pch_refclk(dev); drm_mode_config_reset(dev); + /* Interrupts have to enabled so that any batches that are completed + * when the context is restarted are caught so that the ring buffer + * does not handle. + */ + intel_runtime_pm_enable_interrupts(dev_priv); + mutex_lock(&dev->struct_mutex); if (i915_gem_init_hw(dev)) { DRM_ERROR("failed to re-initialize GPU, declaring wedged!\n"); @@ -741,9 +747,7 @@ static int i915_drm_resume(struct drm_device *dev) } mutex_unlock(&dev->struct_mutex); - /* We need working interrupts for modeset enabling ... */ - intel_runtime_pm_enable_interrupts(dev_priv); - + /* This must follow the pm enable interrupts */ intel_modeset_init_hw(dev); spin_lock_irq(&dev_priv->irq_lock); -- 1.9.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
