diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-12-11 01:07:12 +0100 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-01-20 22:17:09 +0100 |
commit | b0d1232589df5575c5971224ac4cb30e7e525884 (patch) | |
tree | 21336a0066a019ad4f5bff093a8f824c50540d83 | |
parent | 6c2a75325c800de286166c693e0cd33c3a1c5ec8 (diff) | |
download | linux-stable-b0d1232589df5575c5971224ac4cb30e7e525884.tar.gz linux-stable-b0d1232589df5575c5971224ac4cb30e7e525884.tar.bz2 linux-stable-b0d1232589df5575c5971224ac4cb30e7e525884.zip |
drm: refcounting for crtc framebuffers
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.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
-rw-r--r-- | drivers/gpu/drm/drm_crtc.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 64ef12079528..6dc75ee10079 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1984,8 +1984,21 @@ 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); @@ -2046,6 +2059,8 @@ 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) { @@ -2054,9 +2069,6 @@ 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); @@ -2156,6 +2168,9 @@ 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); @@ -3656,7 +3671,7 @@ 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; @@ -3687,8 +3702,6 @@ 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; @@ -3734,6 +3747,7 @@ 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) { @@ -3742,9 +3756,18 @@ 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; } |