From: Rob Clark rob@ti.com

Since the plane hasn't yet taken a reference, we need to hold a reference while waiting to ensure the backing GEM bo doesn't get freed from under us.

Signed-off-by: Rob Clark rob@ti.com --- drivers/staging/omapdrm/omap_crtc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/omapdrm/omap_crtc.c b/drivers/staging/omapdrm/omap_crtc.c index dade3de..732f2ad 100644 --- a/drivers/staging/omapdrm/omap_crtc.c +++ b/drivers/staging/omapdrm/omap_crtc.c @@ -155,6 +155,7 @@ static void page_flip_cb(void *arg) struct drm_crtc *crtc = arg; struct omap_crtc *omap_crtc = to_omap_crtc(crtc); struct drm_framebuffer *old_fb = omap_crtc->old_fb; + struct drm_gem_object *bo;

omap_crtc->old_fb = NULL;

@@ -165,6 +166,9 @@ static void page_flip_cb(void *arg) * cycle.. for now go for correctness and later figure out speed.. */ omap_plane_on_endwin(omap_crtc->plane, vblank_cb, crtc); + + bo = omap_framebuffer_bo(crtc->fb, 0); + drm_gem_object_unreference_unlocked(bo); }

static int omap_crtc_page_flip_locked(struct drm_crtc *crtc, @@ -173,6 +177,7 @@ static int omap_crtc_page_flip_locked(struct drm_crtc *crtc, { struct drm_device *dev = crtc->dev; struct omap_crtc *omap_crtc = to_omap_crtc(crtc); + struct drm_gem_object *bo;

DBG("%d -> %d", crtc->fb ? crtc->fb->base.id : -1, fb->base.id);

@@ -185,8 +190,15 @@ static int omap_crtc_page_flip_locked(struct drm_crtc *crtc, omap_crtc->event = event; crtc->fb = fb;

- omap_gem_op_async(omap_framebuffer_bo(fb, 0), OMAP_GEM_READ, - page_flip_cb, crtc); + /* + * Hold a reference temporarily until the crtc is updated + * and takes the reference to the bo. This avoids it + * getting freed from under us: + */ + bo = omap_framebuffer_bo(fb, 0); + drm_gem_object_reference(bo); + + omap_gem_op_async(bo, OMAP_GEM_READ, page_flip_cb, crtc);

return 0; }