[Nouveau] [PATCH 2/2] drm/nv20: Enable DATA_ERROR reporting

[Xavier Chantry]

2010/4/14 Marcin Kościelnicki <koriakin at 0x04.net>:
> Signed-off-by: Marcin Kościelnicki <koriakin at 0x04.net>
> ---
>  drivers/gpu/drm/nouveau/nv20_graph.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nv20_graph.c b/drivers/gpu/drm/nouveau/nv20_graph.c
> index d6fc0a8..bd83971 100644
> --- a/drivers/gpu/drm/nouveau/nv20_graph.c
> +++ b/drivers/gpu/drm/nouveau/nv20_graph.c
> @@ -570,7 +570,7 @@ nv20_graph_init(struct drm_device *dev)
>        nv_wr32(dev, NV04_PGRAPH_DEBUG_0, 0xFFFFFFFF);
>        nv_wr32(dev, NV04_PGRAPH_DEBUG_0, 0x00000000);
>        nv_wr32(dev, NV04_PGRAPH_DEBUG_1, 0x00118700);
> -       nv_wr32(dev, NV04_PGRAPH_DEBUG_3, 0xF3CE0475); /* 0x4 = auto ctx switch */
> +       nv_wr32(dev, NV04_PGRAPH_DEBUG_3, 0xF3DE0475); /* 0x4 = auto ctx switch */
>        nv_wr32(dev, NV10_PGRAPH_DEBUG_4, 0x00000000);
>        nv_wr32(dev, 0x40009C           , 0x00000040);
>
> --
> 1.7.0.2
>

Relevant IRC discussion :
02:07 < curro> shining^: hahah, fun, that could explain why someone
decided to disable data errors on nv2x
02:07 < shining^> lol
02:07 < marcheu> curro: yes that's the reason
02:07 < marcheu> we couldn't get A8 to work on nv20 without removing
the error check
02:07 < marcheu> I didn't think anyone would reenable it
02:07 < shining^> ok so it was disabled on purpose. fun. and for that
exact same reason
02:07 < marcheu> yeah
02:08 < shining^> I got many data errors, I just decided to look into
the 2d one first
02:08 < shining^> which was the a8 one
02:08 < marcheu> same on nv40 btw
02:08 < darktama> hmmm, not the same
02:08 < curro> marcheu: ahh, good to know, mwk just sent a patch to reenable it
02:08 < marcheu> curro: yup noticed, wanted to reply but
02:08 < darktama> nv40 rejected A8+blending at draw time with INVALID_STATE
02:08 < darktama> we disabled STATE_CHECK to ignore that
02:09 < marcheu> darktama: I think that's reenabled in the last patch
from mwk though?
02:09 < marcheu> didn't check the bits yet though
02:09 < darktama> iirc STATE_CHECK was bit 29, i'll double-check though
02:10 < marcheu> hmm no nv40 is untouched
02:10 < darktama> nope, mwk turned on DATA_CHECK
02:12 < darktama> on nv40, A8 is valid, and blending is valid, but
combined they're not supposed to work I guess.. they just happen to
accidently for us
02:13 < marcheu> yeah
02:13 < marcheu> error reporting is overrated :p
02:13 < darktama> hehe :)
02:13 < marcheu> maybe we need comments there
02:13 < marcheu> "bit blah is disabled because blah"


So should we just completely give up because it's a dead end, or is it
still worth to investigate further ?
I would like to help, so any crazy ideas about how to find what's
going on are welcome.