Our pixel clock cannot reach a high enough rate for some rather high while common resolutions (like 1080p60).
Make sure we filter the resolutions we cannot reach in our mode_valid function.
Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output") Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- drivers/gpu/drm/sun4i/sun4i_rgb.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c index ab6494818050..923f55039cb1 100644 --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c @@ -54,8 +54,13 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector) static int sun4i_rgb_mode_valid(struct drm_connector *connector, struct drm_display_mode *mode) { + struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector); + struct sun4i_drv *drv = rgb->drv; + struct sun4i_tcon *tcon = drv->tcon; u32 hsync = mode->hsync_end - mode->hsync_start; u32 vsync = mode->vsync_end - mode->vsync_start; + unsigned long rate = mode->crtc_clock * 1000; + long rounded_rate;
DRM_DEBUG_DRIVER("Validating modes...\n");
@@ -87,6 +92,15 @@ static int sun4i_rgb_mode_valid(struct drm_connector *connector,
DRM_DEBUG_DRIVER("Vertical parameters OK\n");
+ rounded_rate = clk_round_rate(tcon->dclk, rate); + if (rounded_rate < rate) + return MODE_CLOCK_LOW; + + if (rounded_rate > rate) + return MODE_CLOCK_HIGH; + + DRM_DEBUG_DRIVER("Clock rate OK\n"); + return MODE_OK; }