PowerPC agpmode issues

Mike michael.heltne at gmail.com
Sat Feb 6 05:06:07 AEDT 2016


True, a permanent patch was needed, but at least we are up and running and
can identify other issues.. In the thread with the patches it is
highlighted that the drivers are broken in the first place

On 5 February 2016 at 17:51, Herminio Hernandez, Jr. <
herminio.hernandezjr at gmail.com> wrote:

> I have already applied his patches on my PowerBook running Jessie to get
> accelerated graphics. However they are only a work around and not a real
> fix so they will be committed to mesa.
>
> On Fri, Feb 5, 2016 at 8:44 AM, Mike <michael.heltne at gmail.com> wrote:
>
>> Herminio,
>>
>> Ok, take a look at this.
>> https://github.com/threader/mesa-11.1.1-ppc-r300-debian or if on stable
>> maybe this is more fitting
>> https://github.com/threader/mesa-10.6.3-ppc-r300-debian - this only
>> fixes the issue for r300 on powerpc though.
>>
>> On 5 February 2016 at 14:32, Herminio Hernandez Jr. <
>> herminio.hernandezjr at gmail.com> wrote:
>>
>>> I have been experiencing the same thing with my iBook and PowerBook.
>>>
>>> Sent from my iPhone
>>>
>>> On Feb 4, 2016, at 8:47 PM, Mike <michael.heltne at gmail.com> wrote:
>>>
>>> Hi.
>>> Managed to get the Radeon R300 running on mesa 11.1.1 with an old 2013
>>> patch from Michel Dànzer, next problem is of course enabling agpmode,
>>> running with pci-mode with radeon.agpmode=-1 works, but is of course slow,
>>> and seems to load the cpu a lot.
>>>
>>> Upon initial investigation i could not initially believe agp could be
>>> this this broken for this long, until i found this.
>>>  "committed with Ben Skeggs on Feb 26, 2013"
>>>
>>> https://github.com/DespairFactor/bullhead/commit/650e1203c11354ba84d69ba445abc0efcfe3890a
>>>
>>> http://lxr.free-electrons.com/source/drivers/gpu/drm/nouveau/nouveau_agp.c?v=4.2
>>> #ifdef __powerpc__
>>> /* Disable AGP by default on all PowerPC machines for
>>> * now -- At least some UniNorth-2 AGP bridges are
>>> * known to be broken: DMA from the host to the card
>>> * works just fine, but writeback from the card to the
>>> * host goes straight to memory untranslated bypassing
>>> * the GATT somehow, making them quite painful to deal
>>> * with...
>>> */
>>> if (nouveau_agpmode == -1)
>>> return false;
>>> #endif
>>>
>>>  and now later this:
>>>
>>> https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/nouveau/nvkm/subdev/pci/agp.c
>>> #ifdef __powerpc__
>>> /* Disable AGP by default on all PowerPC machines for now -- At
>>> * least some UniNorth-2 AGP bridges are known to be broken:
>>> * DMA from the host to the card works just fine, but writeback
>>> * from the card to the host goes straight to memory
>>> * untranslated bypassing that GATT somehow, making them quite
>>> * painful to deal with...
>>> */
>>> mode = 0;
>>> #endif
>>>
>>> All seems to point to serious issues had around the time of change to
>>> ums to kms and a serious regression hitting the linux kernel? No?
>>>
>>> Cheers
>>> -Mike
>>>
>>> _______________________________________________
>>> Linuxppc-dev mailing list
>>> Linuxppc-dev at lists.ozlabs.org
>>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>>>
>>>
>>
>
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