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This get rids of the fallible > constructor call of `DmaMask`. Yes, that's a nice touch, I'll do that. > >> + match self { >> + Self::Turing | Self::Ampere | Self::Ada => 47, >> + Self::Hopper | Self::Blackwell => 52, >> + } >> + } >> +} >> + >> impl TryFrom for Architecture { >> type Error = Error; >> >> @@ -203,6 +216,20 @@ pub(crate) struct Spec { >> revision: Revision, >> } >> >> +/// Reads the GPU architecture from BAR0 registers. >> +/// >> +/// This is a lightweight check used early in probe to determine the correct DMA address width >> +/// before the full [`Spec`] is constructed. >> +pub(crate) fn read_architecture(bar: &Bar0) -> Result { >> + let boot0 = regs::NV_PMC_BOOT_0::read(bar); >> + >> + if boot0.is_older_than_fermi() { >> + return Err(ENODEV); >> + } >> + >> + regs::NV_PMC_BOOT_42::read(bar).architecture() > > Can this just be `Spec::new`? Yes it can. I've fixed it locally, to do Spec::new() early and pass the Spec into Gpu::new(), and it does result in less code here. Good. thanks, -- John Hubbard