On Thu, Jan 22, 2026 at 08:42:02AM +0000, Alice Ryhl wrote:
> On Wed, Jan 21, 2026 at 04:37:46PM -0800, Deborah Brouwer wrote:
> > Currently these warnings, as errors, are preventing Tyr driver
> > from building:
> >
> > error: field `device` is never read
> > --> drivers/gpu/drm/tyr/driver.rs:37:5
> > |
> > 36 | pub(crate) struct TyrDriver {
> > | --------- field in this struct
> > 37 | device: ARef<TyrDevice>,
> > | ^^^^^^
> > |
> > = note: `-D dead-code` implied by `-D warnings`
> > = help: to override `-D warnings` add `#[allow(dead_code)]`
> >
> > error: fields `mali` and `sram` are never read
> > --> drivers/gpu/drm/tyr/driver.rs:196:5
> > |
> > 195 | struct Regulators {
> > | ---------- fields in this struct
> > 196 | mali: Regulator<regulator::Enabled>,
> > | ^^^^
> > 197 | sram: Regulator<regulator::Enabled>,
> > | ^^^^
> >
> > error: aborting due to 2 previous errors
> >
> > Suppress these errors so that the Tyr driver will build.
> >
> > Signed-off-by: Deborah Brouwer <[email protected]>
>
> I still don't understand why I couldn't reproduce it myself, but
> assuming it's not just an 1.80.0 issue, below is my review:
I think the problem is not actually the rust compiler version, but commit
"0242623384c7 rust: driver: let probe() return impl PinInit<Self, Error>"
Tyr probe() used to return a fully initialized Pin<KBox<Self>>, so the
fields existed in an allocated struct which I suppose counted as
“reading” the fields. But now Tyr probe() returns just a PinInit
closure which doesn’t count as reading these fields.
>
> > drivers/gpu/drm/tyr/driver.rs | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
> > index 2a45d0288825..04c865cb4397 100644
> > --- a/drivers/gpu/drm/tyr/driver.rs
> > +++ b/drivers/gpu/drm/tyr/driver.rs
> > @@ -34,6 +34,7 @@
> >
> > #[pin_data(PinnedDrop)]
> > pub(crate) struct TyrDriver {
> > + #[allow(dead_code)]
> > device: ARef<TyrDevice>,
>
> Let's use #[expect(dead_code)] so we remember to remove this when a user
> is added.
Using #[expect(dead_code)] also fails with 'unfulfilled lint expectation'.
So I could keep #[allow(dead_code)] or maybe just use an underscore
_driver too with a comment to explain the issue. What do you think?
>
> > }
> >
> > @@ -193,6 +194,8 @@ struct Clocks {
> >
> > #[pin_data]
> > struct Regulators {
> > + #[allow(dead_code)]
> > mali: Regulator<regulator::Enabled>,
> > + #[allow(dead_code)]
> > sram: Regulator<regulator::Enabled>,
>
> I don't think we intend to ever use these fields - they exist only for
> their destructor. In that case, please prefix them with an underscore
> instead:
>
> #[pin_data]
> struct Regulators {
> _mali: Regulator<regulator::Enabled>,
> _sram: Regulator<regulator::Enabled>,
> }
>
> Alice
