Re: [PATCH] gpu: nova-core: use a single try_pin_init!() block in probe()

["Gary Guo" <gary@garyguo.net>]

On Mon Sep 28, 2026 at 1:15 PM BST, Danilo Krummrich wrote:
> On Mon Sep 28, 2026 at 2:10 PM CEST, Gary Guo wrote:
>> On Mon Sep 28, 2026 at 1:00 PM BST, Danilo Krummrich wrote:
>>> On Mon Sep 28, 2026 at 1:36 PM CEST, Gary Guo wrote:
>>>> I think this doesn't need to use `pin_chain`? You can do
>>>>
>>>>     gpu <- ...,
>>>>
>>>>     _: {
>>>>         #[cfg(...)]
>>>>         gpu.run_self_tests(pdev);
>>>>     }
>>>
>>> Unfortunately, this produces the following error.
>>>
>>> 	error[E0382]: borrow of moved value: `gpu`
>>> 	   --> drivers/gpu/nova-core/driver.rs:140:62
>>> 	    |
>>> 	119 |             gpu <- Gpu::new(
>>> 	    |             --- move occurs because `gpu` has type `core::pin::Pin<&mut gpu::Gpu<'_>>`, which does not implement the `Copy` trait
>>> 	...
>>> 	129 |                 gpu.run_selftests(pdev);
>>> 	    |                 --- value moved here
>>
>>     gpu.as_mut().run_selftests(pdev);
>>
>> should work?
>
> I tried that previously, that gives another error. I didn't dig in further
> though.
>
> 	error[E0596]: cannot borrow `gpu` as mutable, as it is not declared as mutable
> 	   --> drivers/gpu/nova-core/driver.rs:129:17
> 	    |
> 	129 |                 gpu.as_mut().run_selftests(pdev);
> 	    |                 ^^^ cannot borrow as mutable
> 	    |
> 	help: consider changing this to be mutable
> 	    |
> 	119 |             mut gpu <- Gpu::new(
> 	    |             +++
> 	
> 	error: aborting due to 1 previous error

Right, we didn't create the let binding with `mut`.

Does this fix it for you?

diff --git a/rust/pin-init/internal/src/init.rs b/rust/pin-init/internal/src/init.rs
index c5b5a0ce5c4e..031adb46cefe 100644
--- a/rust/pin-init/internal/src/init.rs
+++ b/rust/pin-init/internal/src/init.rs
@@ -446,7 +446,7 @@ fn init_fields(fields: &Punctuated<InitializerField, Token![,]>, pinned: bool) -
                 // Allow `non_snake_case` since the same warning is going to be reported for the
                 // struct field.
                 #[allow(unused_variables, non_snake_case)]
-                let #ident = #guard.let_binding();
+                let mut #ident = #guard.let_binding();
             },
             Member::Unnamed(_) => quote!(),
         };

Best,
Gary