From: Jose Abreu <Jose.Abreu@synopsys.com>
Subject: Re: [PATCH 3/3 v3] drm: bridge/dw-hdmi: Move edid reading to
 .detect() callback
Date: Thu, 4 Aug 2016 14:58:00 +0100
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To: Russell King - ARM Linux <linux@armlinux.org.uk>, Jose Abreu <Jose.Abreu@synopsys.com>
Cc: dri-devel@lists.freedesktop.org, Carlos Palminha <CARLOS.PALMINHA@synopsys.com>, Archit Taneja <architt@codeaurora.org>, David Airlie <airlied@linux.ie>, Fabio Estevam <fabio.estevam@freescale.com>, Daniel Vetter <daniel.vetter@ffwll.ch>, Takashi Iwai <tiwai@suse.de>, Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>, Thierry Reding <treding@nvidia.com>, linux-kernel@vger.kernel.org
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Hi Russell,


On 04-08-2016 11:47, Russell King - ARM Linux wrote:
> On Thu, Aug 04, 2016 at 11:44:51AM +0100, Jose Abreu wrote:
>> When running HDMI compliance tests we noticed that sometimes
>> the edid changes but the get_modes() function is not called
>> so the edid is not updated. Moving the edid reading to the
>> detect() callback ensures that the edid is correctly updated
>> after an hotplug.
> Wouldn't this be a bug in the higher levels of DRM?
>

I am not sure if this is a bug in DRM or a bad implementation of
dw-hdmi. I've seen at least two more drivers that do the edid
reading at the .detect() callback: nouveau and gma500. This is
noticeable if while sending video the edid changes like in a
compliance environment. In the environment that I tested I was
sending video and swapped an edid that had support for AI packets
to another one without support and I noticed that although the
hotplug is generated the edid was not being updated.

Best regards,
Jose Miguel Abreu