[Nouveau] NV50 compute support questions

[Samuel Pitoiset]

On 12/04/2015 09:45 AM, Hans de Goede wrote:
> Hi,
>
> On 02-12-15 19:33, Samuel Pitoiset wrote:
>>
>>
>> On 12/02/2015 04:34 PM, Hans de Goede wrote:
>>> On 01-12-15, Samuel Pitoiset wrote:
>>>
>>>  >>> Ok, here is a MMT trace of vectorAdd:
>>>  >>>
>>>  >>> https://fedorapeople.org/~jwrdegoede/vectorAdd.log.gz
>>>  >>
>>>  >> Hi Hans,
>>>  >>
>>>  >> Thanks a lot.
>>>  >
>>>  > Well, I didn't know but Martin has a GK208...
>>>  > I just tested the compute support on his card and ... it works
>>> without
>>>  > any changes. :-)
>>>  >
>>>  > I'm sorry, I was sure the compute support didn't work on this
>>> chipset.
>>>
>>> No need to be sorry because, ...
>>>
>>>  > Feel free to test on your GK208 and report back if you have problems.
>>>
>>> I've done that, and for me it does not work, if I try to enable compute
>>> support like this:
>>>
>>> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>> b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>> index 461fcaa..ab4ea85 100644
>>> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>> @@ -187,7 +187,7 @@ nvc0_screen_get_param(struct pipe_screen *pscreen,
>>> enum pipe_cap param)
>>>      case PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE:
>>>         return (class_3d >= NVE4_3D_CLASS) ? 1 : 0;
>>>      case PIPE_CAP_COMPUTE:
>>> -      return (class_3d <= NVE4_3D_CLASS) ? 1 : 0;
>>> +      return 1;
>>>      case PIPE_CAP_PREFER_BLIT_BASED_TEXTURE_TRANSFER:
>>>         return nouveau_screen(pscreen)->vram_domain & NOUVEAU_BO_VRAM ?
>>> 1 : 0;
>>>
>>> @@ -246,8 +246,6 @@ nvc0_screen_get_shader_param(struct pipe_screen
>>> *pscreen, unsigned shader,
>>>            return 0;
>>>         break;
>>>      case PIPE_SHADER_COMPUTE:
>>> -      if (class_3d > NVE4_3D_CLASS)
>>> -         return 0;
>>>         break;
>>>      default:
>>>         return 0;
>>> @@ -574,11 +572,10 @@ nvc0_screen_init_compute(struct nvc0_screen
>>> *screen)
>>>      case 0xd0:
>>>         return nvc0_screen_compute_setup(screen, screen->base.pushbuf);
>>>      case 0xe0:
>>> -      return nve4_screen_compute_setup(screen, screen->base.pushbuf);
>>>      case 0xf0:
>>>      case 0x100:
>>>      case 0x110:
>>> -      return 0;
>>> +      return nve4_screen_compute_setup(screen, screen->base.pushbuf);
>>>      default:
>>>         return -1;
>>>      }
>>>
>>> Then as soon as I do startx (which starts gnome-shell) the machine
>>> freezes. This is with mesa-master with the above changes on top.
>>>
>>> X / gnome-shell will happily work of I do not call
>>> nve4_screen_compute_setup()
>>> but then test/trivial/compute fails with a null-ptr exception.
>>>
>>> Do you perhaps have some extra patches in your tree, or am I just
>>> unlucky ?
>>>
>>> I've tested this on both a 4.2 and a 4.4-rc3 kernel.
>>
>> Hi,
>>
>> My bad... I used the wrong card on reator (which is the REing machine
>> of Martin). The primary card is a GK106 and the second one is the
>> GK208. That doesn't explain why I did something wrong but heh? :-)
>>
>> You are right. With those bits added locally, the compute support
>> totally hangs the GPU on my GK208 (NV108), and a reboot is needed.
>>
>> Please give a shot at this branch :
>> http://cgit.freedesktop.org/~hakzsam/mesa/log/?h=nvf0_compute
>>
>> It fixes the initialization of the compute state and allows me to
>> launch 'test_input_global' (ie. ./compute 8) on my GK208 without
>> any dmesg fails. That's a good start but more patches are coming. :-)
>
> This branch indeed works somewhat better, but things still hang on the
>
> test_system_values compute test for me (this is the first test executed
> I did not try the others). So this seems to need more work.

What about test_input_global? test_system_values doesn't work on my side 
but it doesn't hang the GPU. Could you please provide dmesg log?

>
> I've ordered a GTX740 (GK107) card, which should arrive soon, and
> I'll be using that so I can (hopefully) focus on the llvm tgsi bits
> again.

Yeah, GK107 will do the job. :-)

>
>> Btw, according to the trace you sent me, you have a GK208b (NV106).
>
> Right, sorry I thought the differences between GK208 and GK208b would
> not matter.

I don't know exactly the differences between these two chipsets but 
since test_system_values hangs your GPU and not mine, I think they are some.

>
> Thanks for all the input / help!
>
> Regards,
>
> Hans
>
>

-- 
-Samuel