On Sun Aug 30, 2026 at 4:14 AM JST, Danilo Krummrich wrote: > On Sat Aug 29, 2026 at 5:34 AM CEST, Alexandre Courbot wrote: >> On Fri Aug 28, 2026 at 9:09 PM JST, Danilo Krummrich wrote: >>> (Cc: Miguel) >>> >>> On Fri Aug 28, 2026 at 7:33 AM CEST, Alexandre Courbot wrote: >>>> The `kernel` crate now features a replacement for our lossless integer >>>> conversion routines. Switch to the kernel version and remove our own. >>>> >>>> Signed-off-by: Alexandre Courbot <[email protected]> >>>> Reviewed-by: Danilo Krummrich <[email protected]> >>>> Reviewed-by: Eliot Courtney <[email protected]> >>>> --- >>>> drivers/gpu/nova-core/falcon.rs | 12 +- >>>> drivers/gpu/nova-core/falcon/fsp.rs | 4 +- >>>> drivers/gpu/nova-core/fb.rs | 2 +- >>>> drivers/gpu/nova-core/fb/hal/gb100.rs | 6 +- >>>> drivers/gpu/nova-core/firmware.rs | 4 +- >>>> drivers/gpu/nova-core/firmware/booter.rs | 4 +- >>>> drivers/gpu/nova-core/firmware/fwsec.rs | 2 +- >>>> drivers/gpu/nova-core/firmware/fwsec/bootloader.rs | 4 +- >>>> drivers/gpu/nova-core/firmware/gsp.rs | 9 +- >>>> drivers/gpu/nova-core/firmware/tlv.rs | 11 +- >>>> drivers/gpu/nova-core/fsp.rs | 8 +- >>>> drivers/gpu/nova-core/gsp.rs | 4 +- >>>> drivers/gpu/nova-core/gsp/cmdq.rs | 22 +-- >>>> drivers/gpu/nova-core/gsp/fw.rs | 42 ++-- >>>> drivers/gpu/nova-core/gsp/fw/commands.rs | 4 +- >>>> drivers/gpu/nova-core/gsp/sequencer.rs | 2 +- >>>> drivers/gpu/nova-core/mctp.rs | 8 +- >>>> drivers/gpu/nova-core/num.rs | 211 >>>> --------------------- >>>> drivers/gpu/nova-core/vbios.rs | 2 +- >>>> 19 files changed, 78 insertions(+), 283 deletions(-) >>> >>> Please see the discussion in [1]. >>> >>> If we make this change, then the subsequent conversion to const_as!() would >>> need >>> to go through the Rust tree next cycle, which could be a bit of a mess, as >>> I'd >>> expect a bunch of conflicts. >>> >>> Alternatively, we could the the full three cycle dance, or have a signed >>> tag for >>> const_as!() and use it right away. >>> >>> But honestly, the former would just be unnecessary noise. If we don't do the >>> latter, let's just keep the nova-core num module until the dust has been >>> settled. >>> >>> [1] >>> https://lore.kernel.org/all/CANiq72k+-fNWZCwGuQ=FTchxgm-X-f6WR=tG=ercn19ic1e...@mail.gmail.com/ >> >> Maybe I am missing something, but wouldn't the following work? >> >> - rc1 gets tagged, `drm-rust-next` gets the `num::casts` module, >> - This series gets applied to `drm-rust-next`, then `cv!` (without the >> nova-core conversion patch) in `rust-next`, >> - We wait one cycle for `cv!` to trickle down to `drm-rust-next` before >> converting nova-core to use `cv!`. >> >> Would that work? This series doesn't overlap with the const conversions >> that `cv!` covers on purpose, and it would have the benefit of getting >> rid of the local `num` module in nova-core quickly. > > Take casts::usize_into_u32() for instance, drm-rust-next replaces the usage of > it next cycle, but rust-next wants to remove the API from > rust/kernel/num/casts.rs. > > In this case rust-next would need to get rid of the users (including > nova-core), > but drm-rust-next will likely do different changes, so we'd get unnecessary > merge conflicts. > > You can resolve this either by keeping casts::usize_into_u32 and friends > around > for one additional cycle, so that all users we introduce now are gone. Or, > since > there's no rush anyways, we just wait one cycle and use the real thing right > away.
Sorry, I should have explicitly mentioned that `*_into_*` would remain alongside `cv!` for the next cycle. The reason why I think it's preferable to use `casts` in nova-core sooner is that some of the series currently under review (and that will likely be merged next cycle) add more uses of the local `num` methods, making the eentual conversion more painful. If we move to use `casts` early we can at least avoid the churn on those cases that do not use `cv!`.
