[Nouveau] [PATCH 1/2] drm/nv10: Keep the lower bits of PGRAPH_CTX_USER during context switches.

[Ben Skeggs]

On Fri, 2009-11-06 at 16:11 +0100, Francisco Jerez wrote:
> Before this patch they were being reset to zero on every context
> switch instead of leaving the saved value, causing some context
> switching weirdness (the most serious symptom was the memory manager
> corrupting the BOs it migrated because of a malfunctioning M2MF).
> 
> Signed-off-by: Francisco Jerez <currojerez at riseup.net>
Reviewed-by: Ben Skeggs <bskeggs at redhat.com>

> ---
>  drivers/gpu/drm/nouveau/nv10_graph.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nv10_graph.c b/drivers/gpu/drm/nouveau/nv10_graph.c
> index cf5c9c4..6bf6804 100644
> --- a/drivers/gpu/drm/nouveau/nv10_graph.c
> +++ b/drivers/gpu/drm/nouveau/nv10_graph.c
> @@ -673,7 +673,8 @@ int nv10_graph_load_context(struct nouveau_channel *chan)
>  	nv10_graph_load_pipe(chan);
>  
>  	nv_wr32(dev, NV10_PGRAPH_CTX_CONTROL, 0x10010100);
> -	nv_wr32(dev, NV10_PGRAPH_CTX_USER, chan->id << 24);
> +	tmp = nv_rd32(dev, NV10_PGRAPH_CTX_USER);
> +	nv_wr32(dev, NV10_PGRAPH_CTX_USER, (tmp & 0xffffff) | chan->id << 24);
>  	tmp = nv_rd32(dev, NV10_PGRAPH_FFINTFC_ST2);
>  	nv_wr32(dev, NV10_PGRAPH_FFINTFC_ST2, tmp & 0xcfffffff);
>  	return 0;