drm/sun4i: DW HDMI: Lower max. supported rate for H6

Currently resolutions with pixel clock higher than 340 MHz don't work
with H6 HDMI controller. They just produce a blank screen.

Limit maximum pixel clock rate to 340 MHz until scrambling is supported.

Cc: stable@vger.kernel.org # 5.0
Fixes: 40bb9d3147 ("drm/sun4i: Add support for H6 DW HDMI controller")
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190324190609.32721-1-jernej.skrabec@siol.net
This commit is contained in:
Jernej Skrabec 2019-03-24 20:06:09 +01:00 committed by Maxime Ripard
parent 3df1af984b
commit cd9063757a
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GPG Key ID: E3EF0D6F671851C5
1 changed files with 7 additions and 2 deletions

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@ -48,8 +48,13 @@ static enum drm_mode_status
sun8i_dw_hdmi_mode_valid_h6(struct drm_connector *connector,
const struct drm_display_mode *mode)
{
/* This is max for HDMI 2.0b (4K@60Hz) */
if (mode->clock > 594000)
/*
* Controller support maximum of 594 MHz, which correlates to
* 4K@60Hz 4:4:4 or RGB. However, for frequencies greater than
* 340 MHz scrambling has to be enabled. Because scrambling is
* not yet implemented, just limit to 340 MHz for now.
*/
if (mode->clock > 340000)
return MODE_CLOCK_HIGH;
return MODE_OK;