DDC: no ddc bus - possible BIOS bug

[屋国遥]

2011/1/4 Alex Deucher <alexdeucher at gmail.com>:
> 2010/12/30 屋国遥 <hyagni at gmail.com>:
>> 2010/12/31 Alex Deucher <alexdeucher at gmail.com>:
>>> On Thu, Dec 30, 2010 at 10:25 AM, 屋国遥 <hyagni at gmail.com> wrote:
>>>> Hello, all.
>>>>
>>>> I am trying to make dual-head environment on Mac Pro with Ubuntu
>>>> 10.10.  My Mac Pro has the Radeon HD 2600 XT graphic card, so I decided
>>>> to use the radeon driver.
>>>>
>>>> Now, I connect two monitors (the same SAMSUNG monitors) and boot the
>>>> system and X, one display works well, but the other is not recognized.
>>>> In dmesg, I found out the following error message.
>>>>
>>>> I googled the message and found
>>>> <http://www.mail-archive.com/xorg-driver-ati@lists.x.org/msg16768.html>
>>>> and <https://bugs.freedesktop.org/show_bug.cgi?id=29255>.  Referring
>>>> to these posts, I upgraded the kernel to 2.6.36
>>>> (http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.36-maverick/) and
>>>> also graphic drivers (https://launchpad.net/~xorg-edgers/+archive/ppa).
>>>>
>>>> However, the same error is displayed.
>>>>
>>>> I am sorry to say that I have no idea how to use Alex's patch to
>>>> `radeon_atombios.c' because of my poor knowledge of Linux.
>>>> Is not this change included in the recent kernel or drivers?
>>>>
>>>>
>>>> Because dual-head environment works successfully on Mac, I suspect the
>>>> monitor or graphic card has no problem.
>>>>
>>>
>>> You will need a custom patch for your system.  That patch referenced
>>> in the above thread only applies to evergreen chips.  I suspect apple
>>> forgot to specify the ddc assignment for one of the heads in their
>>> vbios and their driver most likely use hardcoded values.  Please send
>>> me a copy of the vbios from your system, and I'll send you a patch to
>>> fix it.  Also please attach the pci device and subsystem ids for your
>>> card (lspci -vnn).  Also, what connectors does your card actually
>>> have?  Two DVI-I?  Two DVI-I and one TV-out?  It looks like some of
>>> the encoder mapping might be wrong on your system too.  I can help get
>>> that fixed up as well.
>>>
>>> To get the vbios:
>>> (as root)
>>> (use lspci to get the bus id)
>>> cd /sys/bus/pci/devices/<pci bus id>
>>> echo 1 > rom
>>> cat rom > /tmp/vbios.rom
>>> echo 0 > rom
>>>
>>> Alex
>>
>> Hi, Alex.
>> Thank you for your fast reply.
>>
>
> The attached patch should fix it.  I think Apple supports TV-out via a
> DVI to TV dongle, so you should see a DIN connector with this patch,
> but both DVI's should work correctly.
>
> Alex

Hello, Alex

Your patch worked perfectly.  Both DVI is found now.

Thank you.

>
>> I understood the situation.
>>
>> My card has just two DVI-I connectors, no TV-out.
>> The attached file is vbios.rom.
>> lspci -vnn result is the following (only the section of VGA controller).
>>
>> 02:00.0 VGA compatible controller [0300]: ATI Technologies Inc RV630
>> [Radeon HD 2600XT] [1002:9588] (prog-if 00 [VGA controller])
>>        Subsystem: Apple Computer Inc. Device [106b:00a6]
>>        Physical Slot: 1
>>        Flags: bus master, fast devsel, latency 0, IRQ 56
>>        Memory at 80000000 (64-bit, prefetchable) [size=256M]
>>        Memory at 90a20000 (64-bit, non-prefetchable) [size=64K]
>>        I/O ports at 2000 [size=256]
>>        Expansion ROM at 90a00000 [disabled] [size=128K]
>>        Capabilities: <access denied>
>>        Kernel driver in use: radeon
>>        Kernel modules: radeon
>>
>>
>> --
>> Haruka YAGNI
>> hyagni at gmail.com
>>
>



-- 
Haruka YAGNI
hyagni at gmail.com