From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH 29/37] drm: refcounting for crtc framebuffers Date: Wed, 12 Dec 2012 14:07:09 +0100 Message-ID: <1355317637-16742-30-git-send-email-daniel.vetter@ffwll.ch> References: <1355317637-16742-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1355317637-16742-1-git-send-email-daniel.vetter-/w4YWyX8dFk@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xorg-driver-ati-bounces+gcfxda-xorg-driver-ati=m.gmane.org-go0+a7rfsptAfugRpC6u6w@public.gmane.org Errors-To: xorg-driver-ati-bounces+gcfxda-xorg-driver-ati=m.gmane.org-go0+a7rfsptAfugRpC6u6w@public.gmane.org To: DRI Development Cc: Nouveau Dev , Intel Graphics Development , Radeon Dev , Daniel Vetter List-Id: dri-devel@lists.freedesktop.org With the prep patch to encapsulate ->set_crtc calls, this is now rather easy. Hooray for inconsistent semantics between ->set_crtc and ->page_flip, where the driver callback is supposed to update the fb pointer, and ->update_plane, where the drm core does the same. Also, since the drm core functions check crtc->fb before calling into driver callbacks, we can't really reduce the critical sections protected by the mode_config locks. Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_crtc.c | 37 ++++++++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 229853e..6562eba 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1983,8 +1983,21 @@ out: int drm_mode_set_config_internal(struct drm_mode_set *set) { struct drm_crtc *crtc = set->crtc; + struct drm_framebuffer *fb, *old_fb; + int ret; + + old_fb = crtc->fb; + fb = set->fb; - return crtc->funcs->set_config(set); + ret = crtc->funcs->set_config(set); + if (ret == 0) { + if (old_fb) + drm_framebuffer_unreference(old_fb); + if (fb) + drm_framebuffer_reference(fb); + } + + return ret; } EXPORT_SYMBOL(drm_mode_set_config_internal); @@ -2045,6 +2058,8 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, goto out; } fb = crtc->fb; + /* Make refcounting symmetric with the lookup path. */ + drm_framebuffer_reference(fb); } else { fb = drm_framebuffer_lookup(dev, crtc_req->fb_id); if (!fb) { @@ -2053,9 +2068,6 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, ret = -EINVAL; goto out; } - /* fb is protect by the mode_config lock, so drop the - * ref immediately */ - drm_framebuffer_unreference(fb); } mode = drm_mode_create(dev); @@ -2155,6 +2167,9 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, ret = drm_mode_set_config_internal(&set); out: + if (fb) + drm_framebuffer_unreference(fb); + kfree(connector_set); drm_mode_destroy(dev, mode); drm_modeset_unlock_all(dev); @@ -3673,7 +3688,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev, struct drm_mode_crtc_page_flip *page_flip = data; struct drm_mode_object *obj; struct drm_crtc *crtc; - struct drm_framebuffer *fb; + struct drm_framebuffer *fb = NULL, *old_fb = NULL; struct drm_pending_vblank_event *e = NULL; unsigned long flags; int hdisplay, vdisplay; @@ -3704,8 +3719,6 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev, fb = drm_framebuffer_lookup(dev, page_flip->fb_id); if (!fb) goto out; - /* fb is protect by the mode_config lock, so drop the ref immediately */ - drm_framebuffer_unreference(fb); hdisplay = crtc->mode.hdisplay; vdisplay = crtc->mode.vdisplay; @@ -3751,6 +3764,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev, (void (*) (struct drm_pending_event *)) kfree; } + old_fb = crtc->fb; ret = crtc->funcs->page_flip(crtc, fb, e); if (ret) { if (page_flip->flags & DRM_MODE_PAGE_FLIP_EVENT) { @@ -3759,9 +3773,18 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev, spin_unlock_irqrestore(&dev->event_lock, flags); kfree(e); } + /* Keep the old fb, don't unref it. */ + old_fb = NULL; + } else { + /* Unref only the old framebuffer. */ + fb = NULL; } out: + if (fb) + drm_framebuffer_unreference(fb); + if (old_fb) + drm_framebuffer_unreference(old_fb); drm_modeset_unlock_all(dev); return ret; } -- 1.7.10.4