[Nouveau] Problems getting nouveau to work with either Geforce GT710 or Geforce 9800GT on ARM Cortex-A9

[Luís Mendes]

Hi Rob, Ilia,

Thanks for your information.

I'll try to have a look into the nouveau code... maybe I can find why
the dma fence doesn't complete. In the amdgpu and radeon drivers I am
being able to get further with the ARM platform, may be I can compare
how they're handling the dma transfers, despite I am getting gpu
lockups after a while of playing videos on ARM with AMD cards too, but
at least it is going a lot further.

Can you point me the files or functions in the nouveau code, where the
initialization tests dma transfers are started? I can try to find
them, but this could save me some time.

Thanks,
Luís

On Thu, Jan 25, 2018 at 2:47 PM, Rob Clark <robdclark at gmail.com> wrote:
> On Thu, Jan 25, 2018 at 8:57 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> On Thu, Jan 25, 2018 at 8:47 AM, Luís Mendes <luis.p.mendes at gmail.com> wrote:
>>> Sorry for alI these individual emails, but I think is more readable
>>> this way, by having each independent information in a separate email.
>>>
>>> I also have these additional cards that I can try: Gefoce GT 1030 and
>>> Geforce GTX 1050 Ti.
>>>
>>> I have tried Geforce GT 1030 and it is working nicely but without
>>> hardware acceleration. Without the hardware acceleration I am able to
>>> get into X (Ubuntu Mate 17.10) and run glmark2.
>>> dmesg follows in attachment.
>>
>> This is a GP108 for which you need not-yet-upstream code to get acceleration.
>>
>>>
>>> I believe this indicates there is no issue with cards initialization,
>>> but is rather something to do with the hardware acceleration code.
>>
>> Someone associated with (or working at?) RH was investigating this for
>> some server-type ARM board with PCIe slots. (Was it you? Rob Clark,
>> CC'd, will remember who it was, and may be able to point you in an
>> appropriate direction.) I think that there were various odd issues
>> with coherency which remained only lightly diagnosed. Note that all
>> your boots instantaneously print "GPU lockup, have a nice day".
>> Everything after that is largely irrelevant.
>
> well, I don't actually have any ARM board w/ PCIe yet.. although I
> would expect that drm_cflush* being no-ops on arm/arm64 isn't likely
> to help things.
>
> BR,
> -R
>
>> This happens when it tries to execute some very basic things and sees
>> that there is no progress. This means sticking a command buffer on the
>> DMA ring, letting the GPU execute it, and making sure that the fence
>> is hit as seen by the CPU. I would recommend tracking down why the
>> accel doesn't work (i.e. you get that message), and not worry about
>> little details like "image appears on screen".
>>
>> Unfortunately the initialization logic in nouveau is a giant pile of
>> spaghetti (with various arguably good reasons, but it doesn't change
>> the end result), so tracking down exactly what fails in the GPU init
>> will be a bit of an undertaking. You should join #nouveau on
>> irc.freenode.net and get some additional advice there.
>>
>> Good luck,
>>
>>   -ilia