Re: PowerPC agpmode issues

From: Mike <michael.heltne@gmail.com>
To: "Herminio Hernandez, Jr." <herminio.hernandezjr@gmail.com>
Cc: Pranith Kumar <bobby.prani@gmail.com>,
	"open list:LINUX FOR POWERPC..." <linuxppc-dev@lists.ozlabs.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: Re: PowerPC agpmode issues
Date: Fri, 5 Feb 2016 19:59:23 +0000	[thread overview]
Message-ID: <CANtoAtN6U9LdKQrFbX9GLOHwwQGDQyfaczf7uHY1SsjT=PWKjw@mail.gmail.com> (raw)
In-Reply-To: <CAJRA9dw=DsiBYUwW0Q-GqALYaVVVkEQKN-LeeTShOq71Zn8X-A@mail.gmail.com>

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Excellent work!

On 5 February 2016 at 19:46, Herminio Hernandez, Jr. <
herminio.hernandezjr@gmail.com> wrote:

> Yeah that is the thread I am on
>
> On Fri, Feb 5, 2016 at 1:44 PM, Mike <michael.heltne@gmail.com> wrote:
>
>> Thanks, found this now -
>> https://www.mail-archive.com/search?l=mesa-dev@lists.freedesktop.org&q=subject:%22%5C%5BMesa%5C-dev%5C%5D+gallium+r300+driver+for+PowerPC%22&o=newest&f=1
>>
>>
>> On 5 February 2016 at 18:08, Herminio Hernandez, Jr. <
>> herminio.hernandezjr@gmail.com> wrote:
>>
>>> Yeah the issue is with the driOpenDriver function at least that what I
>>> think from what I saw in gdb.
>>>
>>> On Fri, Feb 5, 2016 at 12:06 PM, Mike <michael.heltne@gmail.com> wrote:
>>>
>>>> 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@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@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@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@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@lists.ozlabs.org
>>>>>>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>

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