Re: [PATCH 1/2] net: hisilicon: hns_mdio: remove incorrect ACPI_PTR annotation

[Arnd Bergmann]

On Wed, Feb 26, 2025, at 04:21, Jijie Shao wrote:
> on 2025/2/26 0:33, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@xxxxxxxx>
>>
>> Building with W=1 shows a warning about hns_mdio_acpi_match being unused when
>> CONFIG_ACPI is disabled:
>>
>> drivers/net/ethernet/hisilicon/hns_mdio.c:631:36: error: unused variable 'hns_mdio_acpi_match' [-Werror,-Wunused-const-variable]
>>
>> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>> ---
>>   drivers/net/ethernet/hisilicon/hns_mdio.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns_mdio.c b/drivers/net/ethernet/hisilicon/hns_mdio.c
>> index a1aa6c1f966e..6812be8dc64f 100644
>> --- a/drivers/net/ethernet/hisilicon/hns_mdio.c
>> +++ b/drivers/net/ethernet/hisilicon/hns_mdio.c
>> @@ -640,7 +640,7 @@ static struct platform_driver hns_mdio_driver = {
>>   	.driver = {
>>   		   .name = MDIO_DRV_NAME,
>>   		   .of_match_table = hns_mdio_match,
>> -		   .acpi_match_table = ACPI_PTR(hns_mdio_acpi_match),
>> +		   .acpi_match_table = hns_mdio_acpi_match,
>>   		   },
>>   };
>
>
> But I think it can be changed to:
>
> + #ifdef CONFIG_ACPI
> static const struct acpi_device_id hns_mdio_acpi_match[] = {
> 	{ "HISI0141", 0 },
> 	{ },
> };
> MODULE_DEVICE_TABLE(acpi, hns_mdio_acpi_match);
> + #endif
>

That would of course avoid the build warning, but otherwise
would be worse: the only reason ACPI_PTR()/of_match_ptr() exist
is to work around drivers that have to put their device ID
table inside of an #ifdef for some other reason. Adding the
#ifdef to work around an incorrect ACPI_PTR() makes no sense.

     Arnd