This is a note to let you know that I've just added the patch titled
drm/sun4i: DW HDMI: Lower max. supported rate for H6
to the 5.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-sun4i-dw-hdmi-lower-max.-supported-rate-for-h6.patch
and it can be found in the queue-5.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cd9063757a227cf31ebf5391ccda2bf583b0806e Mon Sep 17 00:00:00 2001
From: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
Date: Sun, 24 Mar 2019 20:06:09 +0100
Subject: drm/sun4i: DW HDMI: Lower max. supported rate for H6
From: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
commit cd9063757a227cf31ebf5391ccda2bf583b0806e upstream.
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@xxxxxxxxxxxxxxx # 5.0
Fixes: 40bb9d3147b2 ("drm/sun4i: Add support for H6 DW HDMI controller")
Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190324190609.32721-1-jernej.skrabec@xxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -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;
Patches currently in stable-queue which might be from jernej.skrabec@xxxxxxxx are
queue-5.0/drm-sun4i-dw-hdmi-lower-max.-supported-rate-for-h6.patch
