[Nouveau] nouveau broken on Riva TNT2 in 5.13.0-rc4: NULL pointer dereference in nouveau_bo_sync_for_device

[Ondrej Zary]

On Wednesday 09 June 2021, Christian König wrote:
> Am 09.06.21 um 08:57 schrieb Ondrej Zary:
> > [SNIP]
> >> Thanks for the heads up. So the problem with my patch is already fixed,
> >> isn't it?
> > The NULL pointer dereference in nouveau_bo_wr16 introduced in
> > 141b15e59175aa174ca1f7596188bd15a7ca17ba was fixed by
> > aea656b0d05ec5b8ed5beb2f94c4dd42ea834e9d.
> >
> > That's the bug I hit when bisecting the original problem:
> > NULL pointer dereference in nouveau_bo_sync_for_device
> > It's caused by:
> > # first bad commit: [e34b8feeaa4b65725b25f49c9b08a0f8707e8e86] drm/ttm: merge ttm_dma_tt back into ttm_tt
> 
> Good that I've asked :)
> 
> Ok that's a bit strange. e34b8feeaa4b65725b25f49c9b08a0f8707e8e86 was 
> created mostly automated.
> 
> Do you have the original backtrace of that NULL pointer deref once more?

The original backtrace is here: https://lkml.org/lkml/2021/6/5/350

-- 
Ondrej Zary