Re: [PATCH 09/13] gpu: nova-core: wait for FSP boot earlier

[Alexandre Courbot]

On Mon Jun 15, 2026 at 11:40 PM JST, Eliot Courtney wrote:
> For GPU architectures that use FSP CoT boot, ensure that FSP itself is
> booted before trying to use it. In particular, accessing registers like
> `NV_USABLE_FB_SIZE_IN_MB` for `FbHal::vidmem_size` should happen after
> FSP is booted. Currently, we wait for FSP boot too late. So, move this
> wait to a new preboot phase.

Can you give a source for why `NV_USABLE_FB_SIZE_IN_MB` depends on the
FSP?

<...>
> diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
> index b3c91731db45..ca37892c3b38 100644
> --- a/drivers/gpu/nova-core/gpu.rs
> +++ b/drivers/gpu/nova-core/gpu.rs
> @@ -295,7 +295,8 @@ pub(crate) fn new(
>                  dev_info!(pdev,"NVIDIA ({})\n", spec);
>              })?,
>  
> -            // We must wait for GFW_BOOT completion before doing any significant setup on the GPU.
> +            // We must wait for some architecture specific setup to complete before doing any
> +            // significant setup on the GPU.
>              _: {
>                  let hal = hal::gpu_hal(spec.chipset);
>                  let dma_mask = hal.dma_mask();
> @@ -304,8 +305,8 @@ pub(crate) fn new(
>                  // still constructing it, so no concurrent DMA allocations can exist.
>                  unsafe { pdev.dma_set_mask_and_coherent(dma_mask)? };
>  
> -                hal.wait_gfw_boot_completion(bar)
> -                    .inspect_err(|_| dev_err!(pdev, "GFW boot did not complete\n"))?;
> +                hal.wait_preboot_completion(bar, spec.chipset)
> +                    .inspect_err(|_| dev_err!(pdev, "preboot firmware did not complete\n"))?;

It seems like there is going to be a need to make the `Fsp` available at
the `Gpu` level to support the vGPU needs [1].

So I guess the solution here will be to just instanciate the `Fsp` as we
do for e.g. the falcons if we are on Hopper+. Hopefully that will also
achieve what this patch intends to do.

[1] https://lore.kernel.org/all/DJAZRULU1QHZ.2NSTR1ZPOQUSN@xxxxxxxxxx/