From patchwork Fri Aug 8 20:39:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 378486 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id EDB7814011E; Sat, 9 Aug 2014 06:45:28 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1XFr2U-0001BO-AK; Fri, 08 Aug 2014 20:45:26 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1XFr2M-00015F-EH for kernel-team@lists.ubuntu.com; Fri, 08 Aug 2014 20:45:18 +0000 Received: from c-67-160-228-185.hsd1.ca.comcast.net ([67.160.228.185] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1XFqyy-0000ty-La; Fri, 08 Aug 2014 20:41:49 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1XFqyw-0001Su-NO; Fri, 08 Aug 2014 13:41:46 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.13 168/259] drm/i915: Reorder the semaphore deadlock check, again Date: Fri, 8 Aug 2014 13:39:51 -0700 Message-Id: <1407530482-4483-169-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407530482-4483-1-git-send-email-kamal@canonical.com> References: <1407530482-4483-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Cc: Jani Nikula , Daniel Vetter , Kamal Mostafa , Mika Kuoppala , Chris Wilson X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.13.11.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit a0d036b074b4a5a933e37fcb9bdd6b3cc80a0387 upstream. 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 Signed-off-by: Daniel Vetter Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/i915/i915_irq.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 2093c72..3a10da2 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2392,7 +2392,7 @@ static int semaphore_passed(struct intel_ring_buffer *ring) { struct drm_i915_private *dev_priv = ring->dev->dev_private; struct intel_ring_buffer *signaller; - u32 seqno, ctl; + u32 seqno; ring->hangcheck.deadlock++; @@ -2404,15 +2404,12 @@ static int semaphore_passed(struct intel_ring_buffer *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;