Merely writing zero to the CHn Source Image Format Register is not sufficient to disable a plane, as the programmed register value is not propagated immediately to the current side. This can be seen when using the -P option of modetest: the extra plane is displayed correctly, but does not disappear after exit. Fix this by doing the full update dance using the Blend Control Register, like is done when enabling the plane. Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> --- drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c b/drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c index 850986cee848226a..0e34573c3cb3d032 100644 --- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c +++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c @@ -215,7 +215,10 @@ static int shmob_drm_plane_disable(struct drm_plane *plane, splane->format = NULL; + lcdc_write(sdev, LDBCR, LDBCR_UPC(splane->index)); lcdc_write(sdev, LDBnBSIFR(splane->index), 0); + lcdc_write(sdev, LDBCR, + LDBCR_UPF(splane->index) | LDBCR_UPD(splane->index)); return 0; } -- 2.34.1
