GPU drivers in Linux fedora23 - EDID redundant polling when TV is in standby

[Shmuel Weiss]

Hi All,

I need your help to investigate an issue I have with some TV monitor, it
seems like the DRM or i915 is polling the TV EDID at high frequency even if
the TV is in standby.

I need your guidance to diagnose this problem, and to point me to the code
part which is responsible to read the EDID when an Hot Plug is detected and
polling the TV EDID (i2c request over DDC line).

Thanks in advance,


Shmuel Weiss
email: weiss.shmuel at gmail.com

---------- Forwarded message ----------
From: "Jani Nikula" <jani.nikula at linux.intel.com>
Date: Jun 2, 2017 10:19 AM
Subject: Re: Fwd: GPU drivers in Linux fedora23
To: <weiss.shmuel at gmail.com>
Cc:

On Fri, 02 Jun 2017, Shmuel Weiss <weiss.shmuel at gmail.com> wrote:
> HI,
>
> I saw you're the Author of GPU/DRM driver for Intel

That's a gross exaggeretion of my role; I'm just one of many. ;)

> i wanted to know if you can point me to the part of the code which
> poll the EDID changes when a TV is plugged.  how this mechanism is
> working?

Either we get a hotplug interrupt to check the connector, or if that
doesn't work for some reason, we poll periodically to check if there's
something connected.

> we have an issue where we see the Driver trying to read EDID even the
> TV is in standby, this behavior cause us trouble.

If you have issues, please file a bug over at
https://bugs.freedesktop.org/enter_bug.cgi?product=DRI

> BTW, do you how I can see with which DRM driver the Kernel is actually
> running ? How the plug and play driver selection is working in this
> case in Linux when we install it?

On x86, each driver lists the PCI ID's of the hardware it supports, and
the kernel picks up the correct driver for the hardware.

Try 'lspci -v -s 00:02'

> thanks in advance.

HTH. For future reference, please write to the
dri-devel at lists.freedesktop.org or intel-gfx at lists.freedesktop.org
mailing lists. Writing individual developers does not scale.

BR,
Jani.


--
Jani Nikula, Intel Open Source Technology Center
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