[Nouveau] PFIFO_DMA_PUSHER + Xen + NV30 + questions.

[Younes Manton]

On Fri, Jun 4, 2010 at 5:24 PM, Konrad Rzeszutek Wilk
<konrad.wilk at oracle.com> wrote:
> Hello,
>
> I am kernel engineer working on PV-OPS kernel trying to get it work in Dom0
> with an NVidia (NV30 right now) card.
>
> But there are issues, such as that the
> pv-ops kernel has a different understanding of memory (for details check
> out: http://wiki.xensource.com/xenwiki/XenPVOPSDRM).
>
> I've fleshed out most of them (like GART had the wrong phys addresses,
> ouch!), but the one that I am stumbling at is that I see the PFIFO_DMA_PUSHER,
> which I am to understand means: "Oh, the GPU obj operation you stuck on the
> RAMHT/RAMIN is busted."
>
> So first of, is there a register to poke to find out which DMA operation
> it is talking about ? Or is it pretty fast - so I can surmise that:
>
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:75 - ch0 handle=0x80000001
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:86 - hash=0x00000088
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_insert:141 - insert ch0 0x00000088: h=0x80000001, c=0x80011639
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_ref_add:457 - ch0 h=0x8000000e gpuobj=ffff88000219ac00
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:75 - ch0 handle=0x8000000e
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:86 - hash=0x000000f0
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_insert:141 - insert ch0 0x000000f0: h=0x8000000e, c=0x80000004
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_dma_new:679 - ch0 class=0x003d offset=0x40000 size=0x20
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_dma_new:680 - access=0 target=0
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_new:216 - ch0 size=16 align=16 flags=0x00000006
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_new:224 - gpuobj ffff88000219ac60
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_new:241 - global heap fallback
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_ref_add:457 - ch0 h=0x80000006 gpuobj=ffff88000219ac60
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:75 - ch0 handle=0x80000006
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_hash_handle:86 - hash=0x000000b0
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_ramht_insert:141 - insert ch0 0x000000b0: h=0x80000006, c=0x8000163a
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_channel_alloc: initialised FIFO 0
> [   13.760068] [drm] nouveau 0000:01:00.0: PFIFO_DMA_PUSHER - Ch 0
> [   13.271499] [drm] nouveau 0000:01:00.0: nouveau_gpuobj_dma_new:679 - ch0 class=0x003d offset=0x0 size=0x8000000
>
> the error is for the blobs that have been inserted via _ramht_insert?
> Or should I interogate some register to find out what it thinks is
> wrong?
>
> P.S.
> 1) If you are interested in seeing the git tree and all of the hacks I've
> employed so far:
> git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git dev.experiment.kms
> 2) A serial log on baremetal: http://darnok.org/tst004.baremetal.1
> 3) And on Xen:http://darnok.org/tst004.xen.1 where the PFIFO_DMA_PUSHER
> is the king.

It means the card started fetching unexpected garbage from the ring
buffer. Either you pointed the card at garbage instead of a sensible
buffer (nv10_fifo_create_context for nv30 IIRC) or your initial
pushbuf (submitted by nouveau_dma_init) contains garbage. Or maybe
something else, but based on your log that would be my guess.