On 11/14/25 5:09 PM, John Hubbard wrote: > Pass in a PCI device to Spec::new(), and provide a Display > implementation for boot42, in order to provide a clear, concise report > of what happened: the driver read NV_PMC_BOOT42, and found that the GPU > is not supported. > > For very old GPUs (older than Fermi), the driver still returns ENOTSUPP,
ENODEV, actually, now. thanks, -- John Hubbard > but it does so without a driver-specific dmesg report. That is exactly > appropriate, because if such a GPU is installed, it can only be > supported by Nouveau. And if so, the user is not helped by additional > error messages from Nova. > > Here's the full dmesg output for a Blackwell (not yet supported) GPU: > > NovaCore 0000:01:00.0: Probe Nova Core GPU driver. > NovaCore 0000:01:00.0: Unsupported chipset: boot42 = 0x1b2a1000 (architecture > 0x1b, implementation 0x2) > NovaCore 0000:01:00.0: probe with driver NovaCore failed with error -524 > > Cc: Alexandre Courbot <[email protected]> > Cc: Danilo Krummrich <[email protected]> > Cc: Timur Tabi <[email protected]> > Cc: Joel Fernandes <[email protected]> > Signed-off-by: John Hubbard <[email protected]> > --- > drivers/gpu/nova-core/gpu.rs | 9 ++++++--- > drivers/gpu/nova-core/regs.rs | 18 ++++++++++++++++++ > 2 files changed, 24 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs > index 8e04628ca3d9..2bbc084e2095 100644 > --- a/drivers/gpu/nova-core/gpu.rs > +++ b/drivers/gpu/nova-core/gpu.rs > @@ -191,7 +191,7 @@ pub(crate) struct Spec { > } > > impl Spec { > - fn new(bar: &Bar0) -> Result<Spec> { > + fn new(dev: &device::Device, bar: &Bar0) -> Result<Spec> { > // Some brief notes about boot0 and boot42, in chronological order: > // > // NV04 through NV50: > @@ -216,7 +216,10 @@ fn new(bar: &Bar0) -> Result<Spec> { > return Err(ENODEV); > } > > - Spec::try_from(regs::NV_PMC_BOOT_42::read(bar)) > + let boot42 = regs::NV_PMC_BOOT_42::read(bar); > + Spec::try_from(boot42).inspect_err(|_| { > + dev_err!(dev, "Unsupported chipset: {}\n", boot42); > + }) > } > } > > @@ -268,7 +271,7 @@ pub(crate) fn new<'a>( > bar: &'a Bar0, > ) -> impl PinInit<Self, Error> + 'a { > try_pin_init!(Self { > - spec: Spec::new(bar).inspect(|spec| { > + spec: Spec::new(pdev.as_ref(), bar).inspect(|spec| { > dev_info!(pdev.as_ref(),"NVIDIA ({})\n", spec); > })?, > > diff --git a/drivers/gpu/nova-core/regs.rs b/drivers/gpu/nova-core/regs.rs > index c6e2e08c754b..a53b013f2eca 100644 > --- a/drivers/gpu/nova-core/regs.rs > +++ b/drivers/gpu/nova-core/regs.rs > @@ -67,6 +67,24 @@ pub(crate) fn chipset(self) -> Result<Chipset> { > }) > .and_then(Chipset::try_from) > } > + > + /// Returns the raw architecture value from the register. > + fn architecture_raw(self) -> u8 { > + ((self.0 >> Self::ARCHITECTURE_RANGE.start()) & ((1 << > Self::ARCHITECTURE_RANGE.len()) - 1)) > + as u8 > + } > +} > + > +impl kernel::fmt::Display for NV_PMC_BOOT_42 { > + fn fmt(&self, f: &mut kernel::fmt::Formatter<'_>) -> kernel::fmt::Result > { > + write!( > + f, > + "boot42 = 0x{:08x} (architecture 0x{:x}, implementation 0x{:x})", > + self.0, > + self.architecture_raw(), > + self.implementation() > + ) > + } > } > > // PBUS
