drm/tyr: suppress unread field warnings

Currently the rust compiler warns that certain fields in the TyrDriver are
'never read'. The fields are needed, but they are not read directly, they
are only written into an 'impl PinInit' that is returned by probe.

When warnings are compiled as errors, these warnings prevent Tyr from
building.

Suppress the warnings by adding underscores to the problematic variables.
This allows Tyr to build again.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260123175235.209092-1-deborah.brouwer@collabora.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Author: deborahbrouwer

drivers/gpu/drm/tyr/driver.rs

@@ -34,7 +34,7 @@ pub(crate) type TyrDevice = drm::Device<TyrDriver>;
 
 #[pin_data(PinnedDrop)]
 pub(crate) struct TyrDriver {
-    device: ARef<TyrDevice>,
+    _device: ARef<TyrDevice>,
 }
 
 #[pin_data(PinnedDrop)]
@@ -127,16 +127,16 @@ impl platform::Driver for TyrDriver {
                     coregroup: coregroup_clk,
                 }),
                 regulators <- new_mutex!(Regulators {
-                    mali: mali_regulator,
-                    sram: sram_regulator,
+                    _mali: mali_regulator,
+                    _sram: sram_regulator,
                 }),
                 gpu_info,
         });
 
         let tdev: ARef<TyrDevice> = drm::Device::new(pdev.as_ref(), data)?;
         drm::driver::Registration::new_foreign_owned(&tdev, pdev.as_ref(), 0)?;
 
-        let driver = TyrDriver { device: tdev };
+        let driver = TyrDriver { _device: tdev };
 
         // We need this to be dev_info!() because dev_dbg!() does not work at
         // all in Rust for now, and we need to see whether probe succeeded.
@@ -193,6 +193,6 @@ struct Clocks {
 
 #[pin_data]
 struct Regulators {
-    mali: Regulator<regulator::Enabled>,
-    sram: Regulator<regulator::Enabled>,
+    _mali: Regulator<regulator::Enabled>,
+    _sram: Regulator<regulator::Enabled>,
 }