Re: [3.5 regression] DRM: Massive (EDID-probing?) X startup delay onATI Radeon RV770 (HD4870)

From: Alex Deucher
Date: Mon Aug 06 2012 - 09:43:30 EST

On Sat, Aug 4, 2012 at 12:13 PM, Nix <nix@xxxxxxxxxxxxx> wrote:
> Possibly-relevant info:
> - Two DVI monitors, identical specs, one dual-head graphics card
> (so no VGA switcheroo or awesome-yet-terrifying PRIME madness needed)
> - KMS, Xserver 1.12.3, driver 6.14.6-28 (trunk current as of today),
> Mesa 8.0.4, libdrm 2.4.37
> As of kernel 3.5 EDID probing of the older of my two monitors appears to
> have subtly broken. The log shows that it appears to work -- KMS comes
> up OK and I get a working console -- but then X stops during startup for
> nearly a minute (with both monitors black) before coming back to life
> again and EDID-probing the monitor a further six times for no obvious
> reason. (Full log attached, and xorg.conf, for what little use it is.)
> Something appears to be wrong, but I have no idea what. I've not changed
> anything other than the kernel since my last non-huge-delayed startup
> earlier this week, and both the monitors still work, including the one
> suffering a huge startup delay.

Can you bisect the kernel or profile Xorg and see what's causing it?
There haven't been any i2c changes in the radeon kernel driver in a
while. I'm assuming it's only the kernel that you changed? E.g.,
just to be sure, does booting a different kernel with the same
userspace components work correctly?

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