Re: [PATCH] drm/tyr: suppress unread field warnings

["Danilo Krummrich" <dakr@kernel.org>]

On Thu Jan 22, 2026 at 12:22 PM CET, Mark Brown wrote:
> On Thu, Jan 22, 2026 at 01:58:40AM +0100, Miguel Ojeda wrote:
>
>> From what I understand, this is only reproducible with Rust 1.80.0
>> (unsupported upstream), and was fixed in Rust 1.80.1. Did you
>> reproduce it elsewhere? I asked Mark where his toolchain comes to see
>> what could be done there (e.g. in his distribution).
>> 
>> If it is just in Rust 1.80.0, and if a distribution still uses that
>> one, and for some reason they don't want to use/backport the fix in
>> 1.80.1, then we could consider something more global, i.e. ignoring
>> that lint altogether for that version, since it also fails for another
>> trait in `bounded.rs` (that is why I knew about this).
>
> As I said on the other thread I'm seeing this with what appears to be
> 1.85.0 in Debian stable.

That's pretty odd, I can only reproduce the ones you reported in the linux-next
report with 1.80.0.

If I run 1.85.0, I *instead* see the following ones from clippy:

  CLIPPY [M] drivers/gpu/drm/tyr/tyr.o
warning: operator precedence can trip the unwary
  --> drivers/gpu/drm/tyr/gpu.rs:51:13
   |
51 |             shader_present | u64::from(regs::GPU_SHADER_PRESENT_HI.read(dev, iomem)?) << 32;
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `shader_present | (u64::from(regs::GPU_SHADER_PRESENT_HI.read(dev, iomem)?) << 32)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
   = note: `-W clippy::precedence` implied by `-W clippy::all`
   = help: to override `-W clippy::all` add `#[allow(clippy::precedence)]`

warning: operator precedence can trip the unwary
  --> drivers/gpu/drm/tyr/gpu.rs:55:13
   |
55 |             tiler_present | u64::from(regs::GPU_TILER_PRESENT_HI.read(dev, iomem)?) << 32;
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `tiler_present | (u64::from(regs::GPU_TILER_PRESENT_HI.read(dev, iomem)?) << 32)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence

warning: operator precedence can trip the unwary
  --> drivers/gpu/drm/tyr/gpu.rs:58:26
   |
58 |         let l2_present = l2_present | u64::from(regs::GPU_L2_PRESENT_HI.read(dev, iomem)?) << 32;
   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `l2_present | (u64::from(regs::GPU_L2_PRESENT_HI.read(dev, iomem)?) << 32)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence

I wonder if this is Debian specific?