diff options
| author | Archit Taneja | 2013-04-09 15:26:00 +0300 |
|---|---|---|
| committer | Tomi Valkeinen | 2013-04-11 13:25:57 +0300 |
| commit | b03e14fd4b9f91d0c6be864bf62c75933fa26cac (patch) | |
| tree | ea5e01fc30a6470eeab374bf310d8ea824813f19 /drivers/gpu/drm/omapdrm | |
| parent | bddabbe174cfb6f944baaf13ed5b93c6ee89ec3d (diff) | |
drm/omap: Take a fb reference in omap_plane_update()
When userspace calls SET_PLANE ioctl, drm core takes a reference of the fb and
passes control to the update_plane op defined by the drm driver.
In omapdrm, we have a worker thread which queues framebuffers objects received
from update_plane and displays them at the appropriate time.
It is possible that the framebuffer is destoryed by userspace between the time
of calling the ioctl and apply-worker being scheduled. If this happens, the
apply-worker holds a pointer to a framebuffer which is already destroyed.
Take an extra refernece/unreference of the fb in omap_plane_update() to prevent
this from happening. A reference is taken of the fb passed to update_plane(),
the previous framebuffer (held by plane->fb) is unreferenced. This will prevent
drm from destroying the framebuffer till the time it's unreferenced by the
apply-worker.
This is in addition to the exisitng reference/unreference in update_pin(),
which is taken for the scanout of the plane's current framebuffer, and an
unreference the previous framebuffer.
Signed-off-by: Archit Taneja <archit@ti.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Diffstat (limited to 'drivers/gpu/drm/omapdrm')
| -rw-r--r-- | drivers/gpu/drm/omapdrm/omap_plane.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c index 2882cda6ea19..8d225d7ff4e3 100644 --- a/drivers/gpu/drm/omapdrm/omap_plane.c +++ b/drivers/gpu/drm/omapdrm/omap_plane.c @@ -247,6 +247,12 @@ static int omap_plane_update(struct drm_plane *plane, { struct omap_plane *omap_plane = to_omap_plane(plane); omap_plane->enabled = true; + + if (plane->fb) + drm_framebuffer_unreference(plane->fb); + + drm_framebuffer_reference(fb); + return omap_plane_mode_set(plane, crtc, fb, crtc_x, crtc_y, crtc_w, crtc_h, src_x, src_y, src_w, src_h, |