Message-ID: <AANLkTikEGSZUBy8VZOIUhA8iAPa5p7r9vmN47hiEwSB8@mail.gmail.com>
Date:	Tue, 8 Jun 2010 10:49:31 +1000
From:	Dave Airlie <airlied@...il.com>
To:	Torsten Kaiser <just.for.lkml@...glemail.com>
Cc:	Alex Deucher <alexdeucher@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: radeon blink during probe regression (was Re: Linux 2.6.35-rc2)

(changing subject

On Tue, Jun 8, 2010 at 3:28 AM, Torsten Kaiser
<just.for.lkml@...glemail.com> wrote:
> On Mon, Jun 7, 2010 at 8:52 AM, Dave Airlie <airlied@...il.com> wrote:
>> On Mon, Jun 7, 2010 at 4:32 PM, Alex Deucher <alexdeucher@...il.com> wrote:
>>> On Mon, Jun 7, 2010 at 2:22 AM, Dave Airlie <airlied@...il.com> wrote:
>>>> On Mon, Jun 7, 2010 at 4:09 PM, Torsten Kaiser
>>>> <just.for.lkml@...glemail.com> wrote:
>>>>> The switchoff intervall is ~10 seconds, not 1..2 as I guessed in the first mail.
>>>>> Any idea if there is something in the KMS code that triggers at this intervall?
>>>>
>>>> The new mode probing code happens every 10 seconds, though we
>>>> shouldn't be turning anything on or off with it.
>>>>
>>>> So I suspect the DAC detection table might be doing bad things on your
>>>> hardware, we have had a problem where the dac detect table on one DAC
>>>> would turn the other one off which clearly wasn't what we wanted to
>>>> see.
>>>> ,
>>>
>>> The x300 is a non-atom card, so it uses the legacy load detection
>>> routines which do mess with some of the crtc regs.
>>>
>>
>> Okay I see it now, I'm amazed that I was seeing this issue last week
>> and blaming it on something complete different and only seeing it on
>> one card.
>>
>> I expect its the same problem I'll try and track down a proper fix for
>> it tomorrow.
>
> It really seems to be this polling code.
> After the fix to drivers/char/vt.c the 2.6.35-rc2 kernel now works for
> me without crashing.
>
> I also changed #define DRM_OUTPUT_POLL_PERIOD (10*HZ) to
> #define DRM_OUTPUT_POLL_PERIOD (3*HZ) and now the flickering before X
> starts is at a three second interval. That should prove, that the
> polling from drm_crtc_helper.c is the cause.
>
> After X starts the LCD is stable, but the secondary CRT still flickers
> every 3 seconds.
>
> My hardware is an X300-PCIe card with a VGA-, a DVI-I- and a video output.
> I have a 1280x1024 LCD attached to the DVI-I and an old CRT to the
> VGA. The video output is unused.
> The CRT is normally switched off, but its still detected correctly.
>
> The kernel output from 2.6.34 and 2.6.35-rc2 is here:
> http://lkml.org/lkml/2010/6/6/126
>
> xrandr says:
> Screen 0: minimum 320 x 200, current 2080 x 1024, maximum 4096 x 4096
> DVI-0 connected 1280x1024+0+0 (normal left inverted right x axis y
> axis) 338mm x 270mm
>   1280x1024      60.0*+   75.0
>   1280x960       60.0
>   1152x864       75.0
>   1024x768       75.1     70.1     60.0
>   832x624        74.6
>   800x600        72.2     75.0     60.3     56.2
>   640x480        72.8     75.0     66.7     60.0
>   720x400        70.1
>   640x400        70.0
> VGA-0 connected 800x600+1280+150 (normal left inverted right x axis y
> axis) 280mm x 210mm
>   800x600        72.2*+   75.0     60.3     56.2
>   1280x1024      60.0
>   1024x768       75.1     70.1     60.0
>   640x480        72.8     75.0     60.0
>   720x400        87.8     70.1
> S-video disconnected (normal left inverted right x axis y axis)
>
> If you have something for me to try, just send it. :-)
>
> Torsten
>

Okay here is a patch that seems to work on my test system, but I want
to give it a bit more playing around with before I sent it onwards.

Alex, seem sane to you?

Dave.

Download attachment "0001-drm-radeon-don-t-poll-tv-dac-if-crtc2-is-in-use.patch" of type "application/mbox" (1893 bytes)

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