From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: [PATCH v2 1/5] drm/i915: fix ilk rc6 teardown locking Date: Sat, 19 Mar 2011 18:14:26 -0700 Message-ID: <1300583670-3489-1-git-send-email-ben@bwidawsk.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from cloud01.chad-versace.us (184-106-247-128.static.cloud-ips.com [184.106.247.128]) by gabe.freedesktop.org (Postfix) with ESMTP id F084B9E792 for ; Sat, 19 Mar 2011 18:14:39 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org In the failure cases during rc6 initialization, both the power context and render context may get !refcount without holding struct_mutex. However, on rc6 disabling, the lock is held by the caller. Rearranged the locking so that it's safe in both cases. Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/intel_display.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 49fb54f..2e3c626 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6025,13 +6025,14 @@ intel_alloc_context_page(struct drm_device *dev) struct drm_i915_gem_object *ctx; int ret; + WARN_ON(!mutex_is_locked(&dev->struct_mutex)); + ctx = i915_gem_alloc_object(dev, 4096); if (!ctx) { DRM_DEBUG("failed to alloc power context, RC6 disabled\n"); return NULL; } - mutex_lock(&dev->struct_mutex); ret = i915_gem_object_pin(ctx, 4096, true); if (ret) { DRM_ERROR("failed to pin power context: %d\n", ret); @@ -6043,7 +6044,6 @@ intel_alloc_context_page(struct drm_device *dev) DRM_ERROR("failed to set-domain on power context: %d\n", ret); goto err_unpin; } - mutex_unlock(&dev->struct_mutex); return ctx; @@ -6608,9 +6608,12 @@ void ironlake_enable_rc6(struct drm_device *dev) if (!i915_enable_rc6) return; + mutex_lock(&dev->struct_mutex); ret = ironlake_setup_rc6(dev); - if (ret) + if (ret) { + mutex_unlock(&dev->struct_mutex); return; + } /* * GPU can automatically power down the render unit if given a page @@ -6619,6 +6622,7 @@ void ironlake_enable_rc6(struct drm_device *dev) ret = BEGIN_LP_RING(6); if (ret) { ironlake_teardown_rc6(dev); + mutex_unlock(&dev->struct_mutex); return; } @@ -6636,6 +6640,7 @@ void ironlake_enable_rc6(struct drm_device *dev) I915_WRITE(PWRCTXA, dev_priv->pwrctx->gtt_offset | PWRCTX_EN); I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT); + mutex_unlock(&dev->struct_mutex); } -- 1.7.3.4