From patchwork Tue Oct 21 10:59:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5123561 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0E77FC11AC for ; Tue, 21 Oct 2014 12:15:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 273D4200E9 for ; Tue, 21 Oct 2014 12:15:17 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 064EB200E3 for ; Tue, 21 Oct 2014 12:15:13 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 6C38C15D4; Tue, 21 Oct 2014 11:16:08 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id C5679D19 for ; Tue, 21 Oct 2014 11:16:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 689A61F8A8 for ; Tue, 21 Oct 2014 11:16:06 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 21 Oct 2014 04:16:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617802029" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:16:05 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:59:58 +0800 Message-Id: <1413889294-31328-999-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0998/1094] drm/i915: remove user GTT mappings early during runtime suspend X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Imre Deak Currently user space can access GEM buffers mapped to GTT through existing mappings concurrently while the platform specific suspend handlers are running. Since these handlers may change the HW state in a way that would break such accesses, remove the mappings before calling the handlers. Spotted by Ville. Also Chris pointed out that the lists that i915_gem_release_all_mmaps() walks through need dev->struct_mutex, so take this lock. There is a potential deadlock against a concurrent RPM resume, resolve this by aborting and rescheduling the suspend (Daniel). v2: - take struct_mutex around i915_gem_release_all_mmaps() (Chris, Daniel) Signed-off-by: Imre Deak Reviewed-by: Robert Beckett Signed-off-by: Daniel Vetter (cherry picked from commit d6102977643de5be2d7dc022fcd2c75ffff59a1b) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/i915_drv.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index c83c83b..acb93fa 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -36,6 +36,7 @@ #include #include +#include #include static struct drm_driver driver; @@ -1356,6 +1357,30 @@ static int intel_runtime_suspend(struct device *device) DRM_DEBUG_KMS("Suspending device\n"); /* + * We could deadlock here in case another thread holding struct_mutex + * calls RPM suspend concurrently, since the RPM suspend will wait + * first for this RPM suspend to finish. In this case the concurrent + * RPM resume will be followed by its RPM suspend counterpart. Still + * for consistency return -EAGAIN, which will reschedule this suspend. + */ + if (!mutex_trylock(&dev->struct_mutex)) { + DRM_DEBUG_KMS("device lock contention, deffering suspend\n"); + /* + * Bump the expiration timestamp, otherwise the suspend won't + * be rescheduled. + */ + pm_runtime_mark_last_busy(device); + + return -EAGAIN; + } + /* + * We are safe here against re-faults, since the fault handler takes + * an RPM reference. + */ + i915_gem_release_all_mmaps(dev_priv); + mutex_unlock(&dev->struct_mutex); + + /* * rps.work can't be rearmed here, since we get here only after making * sure the GPU is idle and the RPS freq is set to the minimum. See * intel_mark_idle(). @@ -1381,8 +1406,6 @@ static int intel_runtime_suspend(struct device *device) return ret; } - i915_gem_release_all_mmaps(dev_priv); - del_timer_sync(&dev_priv->gpu_error.hangcheck_timer); dev_priv->pm.suspended = true;