From: Chris Wilson Date: Sat, 19 Jul 2014 11:40:42 +0000 (+0100) Subject: drm/i915: Reorder the semaphore deadlock check, again X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a0d036b074b4a5a933e37fcb9bdd6b3cc80a0387;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git drm/i915: Reorder the semaphore deadlock check, again commit 4be173813e57c7298103a83155c2391b5b167b4c Author: Chris Wilson Date: Fri Jun 6 10:22:29 2014 +0100 drm/i915: Reorder semaphore deadlock check did the majority of the work, but it missed one crucial detail: The check for the unkickable deadlock on this ring must come after the check whether the ring that we are waiting on has already passed its target seqno. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80709 Tested-by: Stefan Huber Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Jani Nikula Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 267f069765ad..c05c84f3f091 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2845,7 +2845,7 @@ static int semaphore_passed(struct intel_engine_cs *ring) { struct drm_i915_private *dev_priv = ring->dev->dev_private; struct intel_engine_cs *signaller; - u32 seqno, ctl; + u32 seqno; ring->hangcheck.deadlock++; @@ -2857,15 +2857,12 @@ static int semaphore_passed(struct intel_engine_cs *ring) if (signaller->hangcheck.deadlock >= I915_NUM_RINGS) return -1; - /* cursory check for an unkickable deadlock */ - ctl = I915_READ_CTL(signaller); - if (ctl & RING_WAIT_SEMAPHORE && semaphore_passed(signaller) < 0) - return -1; - if (i915_seqno_passed(signaller->get_seqno(signaller, false), seqno)) return 1; - if (signaller->hangcheck.deadlock) + /* cursory check for an unkickable deadlock */ + if (I915_READ_CTL(signaller) & RING_WAIT_SEMAPHORE && + semaphore_passed(signaller) < 0) return -1; return 0;