Message ID | 1460697046-23781-8-git-send-email-airlied@gmail.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Fri, Apr 15, 2016 at 03:10:38PM +1000, Dave Airlie wrote: > From: Dave Airlie <airlied@redhat.com> > > We don't need to hold the fb lock around the initialisation, > only around the list manipulaton. > > So do the lock hold only around the register for now. > Signed-off-by: Dave Airlie <airlied@redhat.com> This needs a bit more explanation added: "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." I also double-checked that we don't have any outdated comments that point at the wrong lock, and didn't find any. With the commit message augmented: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/drm_crtc.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c > index 0d75517..1863879 100644 > --- a/drivers/gpu/drm/drm_crtc.c > +++ b/drivers/gpu/drm/drm_crtc.c > @@ -458,21 +458,22 @@ int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, > { > int ret; > > - mutex_lock(&dev->mode_config.fb_lock); > INIT_LIST_HEAD(&fb->filp_head); > fb->dev = dev; > fb->funcs = funcs; > > ret = drm_mode_object_get_reg(dev, &fb->base, DRM_MODE_OBJECT_FB, > - true, drm_framebuffer_free); > + false, drm_framebuffer_free); > if (ret) > goto out; > > + mutex_lock(&dev->mode_config.fb_lock); > dev->mode_config.num_fb++; > list_add(&fb->head, &dev->mode_config.fb_list); > -out: > - mutex_unlock(&dev->mode_config.fb_lock); > > + drm_mode_object_register(dev, &fb->base); > + mutex_unlock(&dev->mode_config.fb_lock); > +out: > return ret; > } > EXPORT_SYMBOL(drm_framebuffer_init); > -- > 2.5.5 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 0d75517..1863879 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -458,21 +458,22 @@ int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, { int ret; - mutex_lock(&dev->mode_config.fb_lock); INIT_LIST_HEAD(&fb->filp_head); fb->dev = dev; fb->funcs = funcs; ret = drm_mode_object_get_reg(dev, &fb->base, DRM_MODE_OBJECT_FB, - true, drm_framebuffer_free); + false, drm_framebuffer_free); if (ret) goto out; + mutex_lock(&dev->mode_config.fb_lock); dev->mode_config.num_fb++; list_add(&fb->head, &dev->mode_config.fb_list); -out: - mutex_unlock(&dev->mode_config.fb_lock); + drm_mode_object_register(dev, &fb->base); + mutex_unlock(&dev->mode_config.fb_lock); +out: return ret; } EXPORT_SYMBOL(drm_framebuffer_init);