From 2c34b850ee1e9f86b41706149d0954eee58757a3 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Sat, 19 Mar 2011 18:14:26 -0700 Subject: [PATCH] drm/i915: fix ilk rc6 teardown locking 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 Signed-off-by: Chris Wilson Reviewed-by: Keith Packard Signed-off-by: Keith Packard --- drivers/gpu/drm/i915/intel_display.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index bcef1c1e83fc..b6f593a6d970 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6713,13 +6713,14 @@ 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); @@ -6731,7 +6732,6 @@ 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; @@ -7295,9 +7295,12 @@ 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 @@ -7306,6 +7309,7 @@ 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; } @@ -7323,6 +7327,7 @@ 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); } -- 2.11.0