Re: [PATCH v4 14/16] net: stmmac: dwmac-s32: add basic NXP S32G/S32R glue driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 31/10/2024 18:24, Jan Petrous wrote:
> On Thu, Oct 31, 2024 at 06:16:46PM +0100, Jan Petrous wrote:
>> On Thu, Oct 31, 2024 at 04:44:45PM +0100, Krzysztof Kozlowski wrote:
>>> On 31/10/2024 15:43, Jan Petrous wrote:
>>>> On Tue, Oct 29, 2024 at 08:13:40AM +0100, Krzysztof Kozlowski wrote:
>>>>> On Mon, Oct 28, 2024 at 09:24:56PM +0100, Jan Petrous (OSS) wrote:
>>>>>> +	plat->init = s32_gmac_init;
>>>>>> +	plat->exit = s32_gmac_exit;
>>>>>> +	plat->fix_mac_speed = s32_fix_mac_speed;
>>>>>> +
>>>>>> +	plat->bsp_priv = gmac;
>>>>>> +
>>>>>> +	return stmmac_pltfr_probe(pdev, plat, &res);
>>>>>> +}
>>>>>> +
>>>>>> +static const struct of_device_id s32_dwmac_match[] = {
>>>>>> +	{ .compatible = "nxp,s32g2-dwmac" },
>>>>>> +	{ .compatible = "nxp,s32g3-dwmac" },
>>>>>> +	{ .compatible = "nxp,s32r-dwmac" },
>>>>>
>>>>> Why do you need three same entries?
>>>>>
>>>>
>>>> We have three different SoCs and in v3 review you told me
>>>> to return all back:
>>>> https://patchwork.kernel.org/comment/26067257/
>>>
>>> It was about binding, not driver.
>>>
>>> I also asked there: use proper fallback and compatibility. Both comments
>>> of course affect your driver, but why choosing only first part?
>>>
>>
>> Does it mean I should remove first two (G2/G3) members from match array
>> and use "nxp,s32r-dwmac" as fallback for G2/G3? And similarly change
>> the bindings to:
>>
>>   compatible:
>>     oneOf:
>>       - const: nxp,s32r-dwmac
>>       - items:
>> 	  - enum:
>> 	      - nxp,s32g2-dwmac
>> 	      - nxp,s32g3-dwmac
>>           - const: nxp,s32r-dwmac
>>
>> And add here, into the driver, those members back when some device
>> specific feature will be needed? Am I understand your hints right?
>>
> 
> Sorry, it's not correct. This way I'm not able to detect S32R which is
> the only one with higher speed.
> 
> Then I could use the G2 as fallback I think, Ie.:
> 
>   compatible:
>     oneOf:
>       - const: nxp,s32g2-dwmac
>       - items:
> 	  - enum:
>               - nxp,s32g3-dwmac
>               - nxp,s32r-dwmac
>            - const: nxp,s32g2-dwmac

I don't understand. In both cases you can 'detect r', if by this you
meant match and bind. I don't care which one is the fallback, but if one
does not work it points to different issues with your code.

Best regards,
Krzysztof