Unverified Commit cd906375 authored Mar 24, 2019 by Jernej Skrabec Committed by Maxime Ripard Apr 05, 2019

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: 40bb9d31 ("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

parent 3df1af98

drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -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;