On 8/27/25 1:19 AM, Alistair Popple wrote: > Set the correct DMA mask. Without this DMA will fail on some setups. > > Signed-off-by: Alistair Popple <[email protected]> > --- > drivers/gpu/nova-core/driver.rs | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs > index 274989ea1fb4a..3e154ffb6be4b 100644 > --- a/drivers/gpu/nova-core/driver.rs > +++ b/drivers/gpu/nova-core/driver.rs > @@ -1,6 +1,9 @@ > // SPDX-License-Identifier: GPL-2.0 > > -use kernel::{auxiliary, bindings, c_str, device::Core, pci, prelude::*, > sizes::SZ_16M, sync::Arc}; > +use kernel::{ > + auxiliary, bindings, c_str, device::Core, dma::Device, dma::DmaMask, > pci, prelude::*, > + sizes::SZ_16M, sync::Arc, > +}; > > use crate::gpu::Gpu; > > @@ -34,6 +37,9 @@ fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> > Result<Pin<KBox<Self > pdev.enable_device_mem()?; > pdev.set_master(); > > + // SAFETY: No DMA allocations have been made yet > + unsafe { pdev.dma_set_mask_and_coherent(DmaMask::new::<48>())? };
Eventually, should be 52 bits wide, rather than 48. Or so I believe from looking at various drivers, including Nouveau (which uses 52-bit for Blackwell) and mlx* (which use a 64-bit mask). However, it works for the current series, because this series only supports Ampere GPUs, and 48 bits suffices for those. So, you could leave this patch as-is, and I'll change 48 --> 52 in the upcoming Hopper/Blackwell series. Or you can change it now. Either way is fine, so: Reviewed-by: John Hubbard <[email protected]> thanks, -- John Hubbard > + > let bar = Arc::pin_init( > pdev.iomap_region_sized::<BAR0_SIZE>(0, > c_str!("nova-core/bar0")), > GFP_KERNEL,
