[ Upstream commit efa31801203ac2f5c6a82a28cb991c7163ee0f1d ] The Allwinner BSP makes sure that we don't end up with a null start delay or with a delay larger than vtotal. The former condition is likely to happen now with the reworked start delay, so make sure we enforce the same boundaries. Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx> Reviewed-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/c9889cf5f7a3d101ef380905900b45a182596f56.1549896081.git-series.maxime.ripard@xxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 3de41de43127b..97a0573cc5145 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -358,8 +358,12 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, struct drm_display_mode *mode) { u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); + u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; - return mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; + if (delay > mode->vtotal) + delay = delay % mode->vtotal; + + return max_t(u16, delay, 1); } static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi, -- 2.20.1
