Commit 119c0814 authored by Rob Clark's avatar Rob Clark Committed by Greg Kroah-Hartman
Browse files

staging: drm/omap: hold a ref to the bo while waiting for flip 



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: default avatarRob Clark <rob@ti.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1004689c

drivers/staging/omapdrm/omap_crtc.c

+14 −2
Original line number Diff line number Diff line
@@ -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;

}