Re: [PATCH] gpu: nova-core: make pramin/buddy optional

["Eliot Courtney" <ecourtney@nvidia.com>]

On Mon Oct 26, 2026 at 1:24 PM JST, Dave Airlie via B4 Relay wrote:
> From: Dave Airlie <airlied@redhat.com>
>
> These aren't used on systems with no framebuffer memory.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
>  drivers/gpu/nova-core/gpu.rs               | 15 +++++++------
>  drivers/gpu/nova-core/mm.rs                | 34 +++++++++++++++---------------
>  drivers/gpu/nova-core/mm/bar_user.rs       | 14 ++++++------
>  drivers/gpu/nova-core/mm/pagetable/map.rs  | 10 ++++-----
>  drivers/gpu/nova-core/mm/pagetable/walk.rs |  2 +-
>  5 files changed, 38 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
> index 4e59072cab50..5d53fde2cdc1 100644
> --- a/drivers/gpu/nova-core/gpu.rs
> +++ b/drivers/gpu/nova-core/gpu.rs
> @@ -564,18 +564,19 @@ pub(crate) fn new<'a>(
>  
>              // Create GPU memory manager owning memory management resources.
>              mm: {
> -                let usable_vram = gsp_static_info.usable_fb_regions.first().ok_or(ENODEV)?;
> -                let buddy_params = GpuBuddyParams {
> -                    base_offset: usable_vram.start,
> -                    size: usable_vram.end - usable_vram.start,
> -                    chunk_size: Alignment::new::<SZ_4K>(),
> -                };
> +                let buddy_params = gsp_static_info.usable_fb_regions.first().map(|usable_vram| {
> +                    GpuBuddyParams {
> +                        base_offset: usable_vram.start,
> +                        size: usable_vram.end - usable_vram.start,
> +                        chunk_size: Alignment::new::<SZ_4K>(),
> +                    }
> +                });

We should probably add a helper method on e.g. Chipset to say which
chips we expect FB on vs not, instead of proceeding with no fb regions
here for ones where we expect there to be one.