Hi Neil, On Wed, Mar 20, 2019 at 9:11 AM Neil Armstrong narmstrong@baylibre.com wrote:

DMT monitors does not necessarely report a maximum TMDS clock in a VSDB EDID extension.

In this case, all modes are wrongly rejected, including the DRM fallback EDID.

This patch only rejects modes whith clock > max_tmds_clock if the max_tmds_clock is specified. This will only reject 4:2:0 HDMI2.0 modes, who reports a clock > max_tmds_clock.

Reported-by: Maxime Jourdan mjourdan@baylibre.com Fixes: d7d8fb7046b6 ("drm/meson: add HDMI div40 TMDS mode") Signed-off-by: Neil Armstrong narmstrong@baylibre.com

---

drivers/gpu/drm/meson/meson_dw_hdmi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c index e28814f4ea6c..563953ec6ad0 100644 --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c @@ -569,7 +569,8 @@ dw_hdmi_mode_valid(struct drm_connector *connector, DRM_DEBUG_DRIVER("Modeline " DRM_MODE_FMT "\n", DRM_MODE_ARG(mode));

    /* If sink max TMDS clock, we reject the mode */

•   if (mode->clock > connector->display_info.max_tmds_clock)
  

•   if (connector->display_info.max_tmds_clock &&
  

•       mode->clock > connector->display_info.max_tmds_clock)
            return MODE_BAD;
  
    /* Check against non-VIC supported modes */
  

-- 2.21.0

Thanks, this patch restores HDMI output with my old 1080p TV which does not specify a max tmds clock in its EDID. (all modes were considered BAD before).

Tested-by: Maxime Jourdan mjourdan@baylibre.com Reviewed-by: Maxime Jourdan mjourdan@baylibre.com