[Nouveau] NV50 compute support questions

[Samuel Pitoiset]

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. :-)

Btw, according to the trace you sent me, you have a GK208b (NV106).

Thanks!

>
> Regards,
>
> Hans