Subject: Re: linux-next: build failure after merge of the driver-core tree

From: Danilo Krummrich <[email-masked]>
Date: Wed, 19 Mar 2025 12:16:39 +0100

Hi Stephen,

On Wed, Mar 19, 2025 at 08:07:46PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the driver-core tree, today's linux-next build (x86_64
> allmodconfig) failed like this:

The following diff should fix the below conflict.

diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index 63c19f140fbd..a08fb6599267 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 
-use kernel::{bindings, c_str, pci, prelude::*};
+use kernel::{bindings, c_str, device::Core, pci, prelude::*};
 
 use crate::gpu::Gpu;
 
@@ -27,7 +27,7 @@ impl pci::Driver for NovaCore {
     type IdInfo = ();
     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
 
-    fn probe(pdev: &mut pci::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+    fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
         dev_dbg!(pdev.as_ref(), "Probe Nova Core GPU driver.\n");
 
         pdev.enable_device_mem()?;

> 
> error[E0053]: method `probe` has an incompatible type for trait
>   --> drivers/gpu/nova-core/driver.rs:30:20
>    |
> 30 |     fn probe(pdev: &mut pci::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
>    |                    ^^^^^^^^^^^^^^^^ types differ in mutability
>    |
>    = note: expected signature `fn(&kernel::pci::Device<Core>, &()) -> core::result::Result<_, _>`
>               found signature `fn(&mut kernel::pci::Device<kernel::device::Normal>, &()) -> core::result::Result<_, _>`
> help: change the parameter type to match the trait
>    |
> 30 |     fn probe(pdev: &kernel::pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
>    |                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> error[E0599]: no method named `enable_device_mem` found for mutable reference `&mut kernel::pci::Device` in the current scope
>   --> drivers/gpu/nova-core/driver.rs:33:14
>    |
> 33 |         pdev.enable_device_mem()?;
>    |              ^^^^^^^^^^^^^^^^^ method not found in `&mut Device`
> 
> error[E0599]: no method named `set_master` found for mutable reference `&mut kernel::pci::Device` in the current scope
>   --> drivers/gpu/nova-core/driver.rs:34:14
>    |
> 34 |         pdev.set_master();
>    |              ^^^^^^^^^^ method not found in `&mut Device`
> 
> error: aborting due to 3 previous errors
> 
> Some errors have detailed explanations: E0053, E0599.
> For more information about an error, try `rustc --explain E0053`.
> 
> Presumably caused by commit
> 
>   7b948a2af6b5 ("rust: pci: fix unrestricted &mut pci::Device")
> 
> interacting with commit
> 
>   54e6baf123fd ("gpu: nova-core: add initial driver stub")
> 
> from the drm tree.
> 
> I have no idea how to fix this, so I have just used the driver-core tree
> from next-20250318 for today.
> 
> -- 
> Cheers,
> Stephen Rothwell