On Tue, Oct 9, 2018 at 1:40 PM Laurent Pinchart
[off-list ref] wrote:

Hi Jernej,

Thank you for the patch.

On Sunday, 7 October 2018 12:38:51 EEST Jernej Skrabec wrote:

quoted

It turns out that even new DW HDMI controllers exhibits same magenta
line issues as older versions.

Enable workaround for v2.12a.

This doesn't affect the platforms I maintain, so I can't really test this, but
I'm wondering whether there could be other platforms using a v2.12a DW HDMI
that wouldn't need the workaround.

My platforms use a previous version, namely v2.01a. The workaround for that
version has been enabled by

commit 9c305eb442f3b371fc722ade827bbf673514123e
Author: Neil Armstrong [off-list ref]
Date:   Fri Feb 23 12:44:37 2018 +0100

    drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs

I haven't paid too much attention to the patch back then, and have now double-
checked the HDMI output on R-Car Gen3. Enabling the workaround doesn't cause
any regression, and reverting the commit doesn't cause any issue either. I
thus wonder whether we shouldn't enable the workaround with count = 1 in the
default case instead of adding new IP core versions to the list. It would be
nice if someone from Synopsys could comment on this.

I hope this comment isn't *incredibly* off-topic, but we encountered a
similar issue with NVIDIA (and I believe AMD) hardware a while back,
related to HDMI. This was due to infoframes not being sent, but
(perhaps) HDMI Audio being enabled.

This was a single vertical(!) line. It was described as "purple", but
not sure that's distinguishable from "magenta" by most people. [ Fixed
by a522946174 on nouveau, sample bug report
https://bugs.freedesktop.org/show_bug.cgi?id=79912 ]

Cheers,

  -ilia