Re: [PATCH v6 1/4] gpu: nova-core: implement Display for Spec

[John Hubbard <jhubbard@nvidia.com>]

On 11/7/25 9:02 PM, Timur Tabi wrote:
> On Fri, 2025-11-07 at 20:39 -0800, John Hubbard wrote:
>> Implement Display for Spec. This simplifies the dev_info!() code for
>> printing banners such as:
>>
>>     NVIDIA (Chipset: GA104, Architecture: Ampere, Revision: a.1)
>>
>> Cc: Alexandre Courbot <acourbot@nvidia.com>
>> Cc: Danilo Krummrich <dakr@kernel.org>
>> Cc: Timur Tabi <ttabi@nvidia.com>
>> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> 
> I'm okay with the entire patch set, but I do have a few questions.

Great!

> 
>> +impl fmt::Display for Spec {
>> +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
>> +        write!(
>> +            f,
>> +            "Chipset: {}, Architecture: {:?}, Revision: {}",
>> +            self.chipset,
>> +            self.chipset.arch(),
>> +            self.revision
>> +        )
>> +    }
>> +}
>> +
>>  /// Structure holding the resources required to operate the GPU.
>>  #[pin_data]
>>  pub(crate) struct Gpu {
>> @@ -206,13 +218,7 @@ pub(crate) fn new<'a>(
>>      ) -> impl PinInit<Self, Error> + 'a {
>>          try_pin_init!(Self {
>>              spec: Spec::new(bar).inspect(|spec| {
>> -                dev_info!(
>> -                    pdev.as_ref(),
>> -                    "NVIDIA (Chipset: {}, Architecture: {:?}, Revision: {})\n",
>> -                    spec.chipset,
>> -                    spec.chipset.arch(),
>> -                    spec.revision
>> -                );
>> +                dev_info!(pdev.as_ref(),"NVIDIA ({})\n", spec);
> 
> I believe that this is the only place where a `Spec` is actually printed.  Does it really make
> sense to implement Display for a single usage?  Do we generally want to implement Display for
> new types?
> 

I agree that it looks a little excessive, but I defer to reviewers
who have a lot more Rust experience, and they requested this during
a review of an earlier version.


thanks,
-- 
John Hubbard