Nouveau - Oct 2025 - [PATCH RFC v2 1/3] gpu: nova-core: register: use field type for Into implementation

Hi Alex,

On 10/9/2025 8:37 AM, Alexandre Courbot wrote:
> The getter method of a field works with the field type, but its setter
> expects the type of the register. This leads to an asymmetry in the
> From/Into implementations required for a field with a dedicated type.
> For instance, a field declared as
> 
>     pub struct ControlReg(u32) {
>         3:0 mode as u8 ?=> Mode;
>         ...
>     }
> 
> currently requires the following implementations:
> 
>     impl TryFrom<u8> for Mode {
>       ...
>     }
> 
>     impl From<Mode> for u32 {
>       ...
>     }
> 
> Change this so the `From<Mode>` now needs to be implemented for `u8`,
> i.e. the primitive type of the field. This is more consistent, and will
> become a requirement once we start using the TryFrom/Into derive macros
> to implement these automatically.
> 
> Reported-by: Edwin Peer <epeer at nvidia.com>
> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
As these are incremental improvements, could you please rebase on top of the v6
bitfield series so it does not conflict?

https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git/log/?h=nova.dev.bitfield.submitted.v6

Thanks.

> On Oct 9, 2025, at 11:17?AM, Joel Fernandes <joelagnelf at
nvidia.com> wrote:
> 
> ?Hi Alex,
> 
>> On 10/9/2025 8:37 AM, Alexandre Courbot wrote:
>> The getter method of a field works with the field type, but its setter
>> expects the type of the register. This leads to an asymmetry in the
>> From/Into implementations required for a field with a dedicated type.
>> For instance, a field declared as
>> 
>>    pub struct ControlReg(u32) {
>>        3:0 mode as u8 ?=> Mode;
>>        ...
>>    }
>> 
>> currently requires the following implementations:
>> 
>>    impl TryFrom<u8> for Mode {
>>      ...
>>    }
>> 
>>    impl From<Mode> for u32 {
>>      ...
>>    }
>> 
>> Change this so the `From<Mode>` now needs to be implemented for
`u8`,
>> i.e. the primitive type of the field. This is more consistent, and will
>> become a requirement once we start using the TryFrom/Into derive macros
>> to implement these automatically.
>> 
>> Reported-by: Edwin Peer <epeer at nvidia.com>
>> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
> 
> As these are incremental improvements, could you please rebase on top of
the v6
> bitfield series so it does not conflict?
> 
>
https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git/log/?h=nova.dev.bitfield.submitted.v6
On second thought, I could just carry this patch on top of my v6 series and
avoid too much conflict.

So if it is ok with you, please only carry the last 2 patches of this series
whenever applying.

For this patch:
Reviewed-by: Joel Fernandes <joelagnelf at nvidia.com>

I will review the other two patches as well. Thanks.

> 
> Thanks.