From 2ddea3fd94889331855ff311ff540e0b182dd216 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Fri, 15 Apr 2016 15:10:41 +1000 Subject: [PATCH] drm/modes: reduce fb_lock to just protecting lists This reduces the fb_lock to just protecting the num_fb/fb_list. "Previously fb refcounting, and especially the weak reference (kref_get_unless_zero) used in fb lookups have been protected by fb_lock. But with the refactoring to share refcounting in the drm_mode_object base class that switched to being protected by idr_mutex, which means fb_lock critical sections can be reduced." Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_crtc.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index e1de47576143..bec2c3282db9 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -433,9 +433,7 @@ static void drm_framebuffer_free(struct kref *kref) * The lookup idr holds a weak reference, which has not necessarily been * removed at this point. Check for that. */ - mutex_lock(&dev->mode_config.fb_lock); drm_mode_object_unregister(dev, &fb->base); - mutex_unlock(&dev->mode_config.fb_lock); fb->funcs->destroy(fb); } @@ -475,9 +473,9 @@ int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, mutex_lock(&dev->mode_config.fb_lock); dev->mode_config.num_fb++; list_add(&fb->head, &dev->mode_config.fb_list); + mutex_unlock(&dev->mode_config.fb_lock); drm_mode_object_register(dev, &fb->base); - mutex_unlock(&dev->mode_config.fb_lock); out: return ret; } @@ -498,12 +496,9 @@ struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev, struct drm_mode_object *obj; struct drm_framebuffer *fb = NULL; - mutex_lock(&dev->mode_config.fb_lock); obj = _object_find(dev, id, DRM_MODE_OBJECT_FB); if (obj) fb = obj_to_fb(obj); - mutex_unlock(&dev->mode_config.fb_lock); - return fb; } EXPORT_SYMBOL(drm_framebuffer_lookup); @@ -526,10 +521,8 @@ void drm_framebuffer_unregister_private(struct drm_framebuffer *fb) dev = fb->dev; - mutex_lock(&dev->mode_config.fb_lock); /* Mark fb as reaped and drop idr ref. */ drm_mode_object_unregister(dev, &fb->base); - mutex_unlock(&dev->mode_config.fb_lock); } EXPORT_SYMBOL(drm_framebuffer_unregister_private); -- 2.20.1