| Message ID | 1454424379-11524-1-git-send-email-tvrtko.ursulin@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Feb 02, 2016 at 02:46:19PM +0000, Tvrtko Ursulin wrote: > From: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > > VMA creation and GEM list management need the big lock. > > v2: > > Mutex unlock ended on the wrong path somehow. (0-day, Julia Lawall) > > Not to mention drm_gem_object_unreference was there in existing > code with no mutex held. > > v3: > > Some callers of i915_gem_object_create_stolen_for_preallocated > already hold the lock so move the mutex into the other caller > as well. > > v4: > > Changed to lockdep_assert_held. (Chris Wilson) > > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > Cc: Chris Wilson <chris@chris-wilson.co.uk> Also Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> :) Daniel, what did you think of having a config option to turn lockdep_assert_held into WARN_ON(!mutex_is_locked()) when lockdep is not fully-enabled? -Chris
On Thu, Feb 11, 2016 at 10:13:30AM +0000, Chris Wilson wrote: > On Tue, Feb 02, 2016 at 02:46:19PM +0000, Tvrtko Ursulin wrote: > > From: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > > > > VMA creation and GEM list management need the big lock. > > > > v2: > > > > Mutex unlock ended on the wrong path somehow. (0-day, Julia Lawall) > > > > Not to mention drm_gem_object_unreference was there in existing > > code with no mutex held. > > > > v3: > > > > Some callers of i915_gem_object_create_stolen_for_preallocated > > already hold the lock so move the mutex into the other caller > > as well. > > > > v4: > > > > Changed to lockdep_assert_held. (Chris Wilson) > > > > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > > Also > Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> > :) > > Daniel, what did you think of having a config option to turn > lockdep_assert_held into WARN_ON(!mutex_is_locked()) when lockdep is not > fully-enabled? I like, and kinda would even go as far as making it the default. But that might upset some performance concious folks, so Kconfig seems fine. Cany you please submit that to a wider audience? Then we'd never have to have this discussion again ;-) Thanks, Daniel
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index c384dc9c8a63..8cb0371673c5 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -635,6 +635,8 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev, if (!drm_mm_initialized(&dev_priv->mm.stolen)) return NULL; + lockdep_assert_held(&dev->struct_mutex); + DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n", stolen_offset, gtt_offset, size); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index f3c036d98b6c..b7ee2f3af856 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2551,12 +2551,16 @@ intel_alloc_initial_plane_obj(struct intel_crtc *crtc, if (size_aligned * 2 > dev_priv->gtt.stolen_usable_size) return false; + mutex_lock(&dev->struct_mutex); + obj = i915_gem_object_create_stolen_for_preallocated(dev, base_aligned, base_aligned, size_aligned); - if (!obj) + if (!obj) { + mutex_unlock(&dev->struct_mutex); return false; + } obj->tiling_mode = plane_config->tiling; if (obj->tiling_mode == I915_TILING_X) @@ -2569,12 +2573,12 @@ intel_alloc_initial_plane_obj(struct intel_crtc *crtc, mode_cmd.modifier[0] = fb->modifier[0]; mode_cmd.flags = DRM_MODE_FB_MODIFIERS; - mutex_lock(&dev->struct_mutex); if (intel_framebuffer_init(dev, to_intel_framebuffer(fb), &mode_cmd, obj)) { DRM_DEBUG_KMS("intel fb init failed\n"); goto out_unref_obj; } + mutex_unlock(&dev->struct_mutex); DRM_DEBUG_KMS("initial plane fb obj %p\n", obj);