[PATCH] etnaviv: force vertex buffers through the MMU

[Philipp Zabel]

On Mon, 2017-01-30 at 11:01 +0100, Lucas Stach wrote:
> This fixes a vertex data corruption issue if some of the vertex streams
> go through the MMU and some don't.
> 
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>

Without this patch I see the two triangles of a simple white QML
Rectangle background sometimes rendered in solid bright colors, as if
randomly one or two of the color components were set to zero for all
vertices. The test case that made this easy to reproduce had two chained
ShaderEffect items in the foreground.
With the patch applied, the aforementioned problems disappear.

Tested-by: Philipp Zabel <p.zabel at pengutronix.de>

> ---
>  src/gallium/drivers/etnaviv/etnaviv_resource.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/src/gallium/drivers/etnaviv/etnaviv_resource.c b/src/gallium/drivers/etnaviv/etnaviv_resource.c
> index aefe65bf0e47..94a8a73997a8 100644
> --- a/src/gallium/drivers/etnaviv/etnaviv_resource.c
> +++ b/src/gallium/drivers/etnaviv/etnaviv_resource.c
> @@ -201,7 +201,10 @@ etna_resource_alloc(struct pipe_screen *pscreen, unsigned layout,
>  
>     size = setup_miptree(rsc, paddingX, paddingY, msaa_xscale, msaa_yscale);
>  
> -   struct etna_bo *bo = etna_bo_new(screen->dev, size, DRM_ETNA_GEM_CACHE_WC);
> +   uint32_t flags = DRM_ETNA_GEM_CACHE_WC;
> +   if (templat->bind & PIPE_BIND_VERTEX_BUFFER)
> +      flags |= DRM_ETNA_GEM_FORCE_MMU;
> +   struct etna_bo *bo = etna_bo_new(screen->dev, size, flags);
>     if (unlikely(bo == NULL)) {
>        BUG("Problem allocating video memory for resource");
>        return NULL;

regards
Philipp