[Mesa-dev] [PATCH] i965/skl: Remove early platform support

[Neil Roberts]

If we go with this patch perhaps it would be good to remove
supports_simd16_3src entirely from brw_device_info and any code that is
referring to it in order to avoid carrying around useless code.
Currently it seems like it would be quite easy to add a new
brw_device_info and forget to add supports_simd16_3src and never notice
that it is redundantly using the fallback.

This would be sort of a pain for me because my Skylake is still one that
needs this workaround but I guess I can just upgrade easily enough.

Regards,
- Neil

Ben Widawsky <benjamin.widawsky at intel.com> writes:

> We do not want bug reports from this early stepping of SKL. Few if any were ever
> shipped outside of Intel to early enabling partners, and none will be sold.
>
> There is a functional change here. If you're using new mesa on an old
> kernel/libdrm, the revid will be -1, and we'll use new SKL values instead of
> early ones (a hopefully irrelevant improvement IMO).
>
> Cc: Jason Ekstrand <jason at jlekstrand.net>
> Cc: Neil Roberts <neil at linux.intel.com>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
>  src/mesa/drivers/dri/i965/brw_device_info.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_device_info.c b/src/mesa/drivers/dri/i965/brw_device_info.c
> index be517e8..fc89221 100644
> --- a/src/mesa/drivers/dri/i965/brw_device_info.c
> +++ b/src/mesa/drivers/dri/i965/brw_device_info.c
> @@ -322,10 +322,7 @@ static const struct brw_device_info brw_device_info_chv = {
>        .max_gs_entries = 640,                        \
>     }
>  
> -static const struct brw_device_info brw_device_info_skl_early = {
> -   GEN9_FEATURES, .gt = 1,
> -   .supports_simd16_3src = false,
> -};
> +#define IS_SKL(devinfo) ((devinfo)->gen == 9 && !(devinfo)->is_broxton)
>  
>  static const struct brw_device_info brw_device_info_skl_gt1 = {
>     GEN9_FEATURES, .gt = 1,
> @@ -376,10 +373,12 @@ brw_get_device_info(int devid, int revision)
>        return NULL;
>     }
>  
> -   if (devinfo->gen == 9 &&
> -       !devinfo->is_broxton &&
> -       (revision == 2 || revision == 3 || revision == -1))
> -      return &brw_device_info_skl_early;
> +   if (IS_SKL(devinfo) && (revision != -1 && revision <= 3)) {
> +      fprintf(stderr,
> +              "i965_dri.so does not support this PCI ID with revision %d.\n",
> +              revision);
> +      return NULL;
> +   }
>  
>     return devinfo;
>  }
> -- 
> 2.5.0