This patch fixed a timing issue that causes a GPU hang when a 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 <deepak.s@xxxxxxxxx> 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. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89600 Signed-off-by: Peter Antoine <peter.antoine@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_drv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 6bb6c47..748ab13 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -734,6 +734,13 @@ static int i915_drm_resume(struct drm_device *dev) intel_init_pch_refclk(dev); drm_mode_config_reset(dev); + /* + * Interrupts have to be enabled before any batches are run. If not the + * GPU will hang. The init_hw will initiate batches to update/restore + * the context. + */ + 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 +748,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html