Subject: Re: linux-next: build failure in final build

From: "Danilo Krummrich" <[email-masked]>
Date: Tue, 20 Jan 2026 11:01:35 +0100

On Tue Jan 20, 2026 at 9:36 AM CET, Alice Ryhl wrote:
> On Mon, Jan 19, 2026 at 11:49:10PM +0100, Danilo Krummrich wrote:
>> (Cc: Boris)
>> 
>> On Mon Jan 19, 2026 at 11:30 PM CET, Mark Brown wrote:
>> > Hi all,
>> >
>> > After merging all trees, today's final linux-next build (arm64
>> > allyesconfig) failed like this:
>> >
>> > error[E0560]: struct `drm_panthor_gpu_info` has no field named `pad0`
>> >   --> /tmp/next/build/drivers/gpu/drm/tyr/gpu.rs:75:13
>> >    |
>> > 75 |             pad0: 0,
>> >    |             ^^^^ `drm_panthor_gpu_info` does not have this field
>> >    |
>> >    = note: available fields are: `selected_coherency`
>> >
>> > Caused by commit
>> >
>> >    8304c44631c37 (drm/tyr: use generated bindings for GpuInfo)
>> 
>> I had a quick look and the problem is that another tree (drm-misc-next) changed
>> the corresponding uAPI struct in commit ea78ec982653 ("drm/panthor: Expose the
>> selected coherency protocol to the UMD") without also changing the Tyr driver.
>> 
>> This diff in Tyr should fix the problem:
>> 
>> diff --git a/drivers/gpu/drm/tyr/gpu.rs b/drivers/gpu/drm/tyr/gpu.rs
>> index 3072562e36e5..0c85f03b8a7d 100644
>> --- a/drivers/gpu/drm/tyr/gpu.rs
>> +++ b/drivers/gpu/drm/tyr/gpu.rs
>> @@ -72,7 +72,7 @@ pub(crate) fn new(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result<Self> {
>>              // TODO: Add texture_features_{1,2,3}.
>>              texture_features: [texture_features, 0, 0, 0],
>>              as_present,
>> -            pad0: 0,
>> +            selected_coherency: 0, // Some variant of `enum drm_panthor_gpu_coherency`.
>>              shader_present,
>>              l2_present,
>>              tiler_present,
>
> Yeah, if that diff can be made in the merge commit, it should solve the
> issue.
>
> If it's easier, we could merge a commit into drm-misc-next that renames
> pad0 to selected_coherency. That would trigger a merge conflict on the
> relevant lines of code.

I think that would make sense as this way it also becomes obvious when the
changes are pulled into the parent DRM tree eventually.