From 4247dae27690a7401fb2860580b0bd4503611c16 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 19 Sep 2012 12:17:16 +0100 Subject: [PATCH] drm/i915: Flush outstanding unpin tasks before pageflipping If we accumulate unpin tasks because we are pageflipping faster than the system can schedule its workers, we can effectively create a pin-leak. The solution taken here is to limit the number of unpin tasks we have per-crtc and to flush those outstanding tasks if we accumulate too many. This should prevent any jitter in the normal case, and also prevent the hang if we should run too fast. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=46991 Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/intel_display.c | 22 ++++++++++++++++------ drivers/gpu/drm/i915/intel_drv.h | 4 +++- 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 2b6ce9b..3d5cd39 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6162,14 +6162,19 @@ static void intel_unpin_work_fn(struct work_struct *__work) { struct intel_unpin_work *work = container_of(__work, struct intel_unpin_work, work); + struct drm_device *dev = work->crtc->dev; - mutex_lock(&work->dev->struct_mutex); + mutex_lock(&dev->struct_mutex); intel_unpin_fb_obj(work->old_fb_obj); drm_gem_object_unreference(&work->pending_flip_obj->base); drm_gem_object_unreference(&work->old_fb_obj->base); - intel_update_fbc(work->dev); - mutex_unlock(&work->dev->struct_mutex); + intel_update_fbc(dev); + mutex_unlock(&dev->struct_mutex); + + BUG_ON(atomic_read(&to_intel_crtc(work->crtc)->unpin_work_count) == 0); + atomic_dec(&to_intel_crtc(work->crtc)->unpin_work_count); + kfree(work); } @@ -6217,9 +6222,9 @@ static void do_intel_finish_page_flip(struct drm_device *dev, atomic_clear_mask(1 << intel_crtc->plane, &obj->pending_flip.counter); - wake_up(&dev_priv->pending_flip_queue); - schedule_work(&work->work); + + queue_work(dev_priv->wq, &work->work); trace_i915_flip_complete(intel_crtc->plane, work->pending_flip_obj); } @@ -6520,7 +6525,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, return -ENOMEM; work->event = event; - work->dev = crtc->dev; + work->crtc = crtc; intel_fb = to_intel_framebuffer(crtc->fb); work->old_fb_obj = intel_fb->obj; INIT_WORK(&work->work, intel_unpin_work_fn); @@ -6545,6 +6550,9 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, intel_fb = to_intel_framebuffer(fb); obj = intel_fb->obj; + if (atomic_read(&intel_crtc->unpin_work_count) >= 2) + flush_workqueue(dev_priv->wq); + ret = i915_mutex_lock_interruptible(dev); if (ret) goto cleanup; @@ -6563,6 +6571,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, * the flip occurs and the object is no longer visible. */ atomic_add(1 << intel_crtc->plane, &work->old_fb_obj->pending_flip); + atomic_inc(&intel_crtc->unpin_work_count); ret = dev_priv->display.queue_flip(dev, crtc, fb, obj); if (ret) @@ -6577,6 +6586,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, return 0; cleanup_pending: + atomic_dec(&intel_crtc->unpin_work_count); atomic_sub(1 << intel_crtc->plane, &work->old_fb_obj->pending_flip); drm_gem_object_unreference(&work->old_fb_obj->base); drm_gem_object_unreference(&obj->base); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index fe71425..5a28230 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -198,6 +198,8 @@ struct intel_crtc { struct intel_unpin_work *unpin_work; int fdi_lanes; + atomic_t unpin_work_count; + /* Display surface base address adjustement for pageflips. Note that on * gen4+ this only adjusts up to a tile, offsets within a tile are * handled in the hw itself (with the TILEOFF register). */ @@ -380,7 +382,7 @@ intel_get_crtc_for_plane(struct drm_device *dev, int plane) struct intel_unpin_work { struct work_struct work; - struct drm_device *dev; + struct drm_crtc *crtc; struct drm_i915_gem_object *old_fb_obj; struct drm_i915_gem_object *pending_flip_obj; struct drm_pending_vblank_event *event; -- 1.7.10.4