Re: [PATCH 1/4] ACPI/APMT: Use stable device ID

[Robin Murphy <robin.murphy@arm.com>]

On 09/07/2026 3:39 pm, Robin Murphy wrote:
> The APMT node format includes a unique identifier, so we can use this as
> the platform device ID to give userspace stable and identifiable device
> names, rather than auto numbering dependent on how the table is parsed.
> 
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Hanjun Guo <guohanjun@huawei.com>
> Cc: Sudeep Holla <sudeep.holla@kernel.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/acpi/arm64/apmt.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/arm64/apmt.c b/drivers/acpi/arm64/apmt.c
> index bb010f6164e5..ba48fcb26d52 100644
> --- a/drivers/acpi/arm64/apmt.c
> +++ b/drivers/acpi/arm64/apmt.c
> @@ -79,7 +79,7 @@ static int __init apmt_add_platform_device(struct acpi_apmt_node *node,
>   	int ret, count;
>   	struct resource res[DEV_MAX_RESOURCE_COUNT];
>   
> -	pdev = platform_device_alloc(DEV_NAME, PLATFORM_DEVID_AUTO);
> +	pdev = platform_device_alloc(DEV_NAME, node->id);

Per the Sashiko comment, while I really wouldn't expect it to be an 
issue in practice, I guess we could explicitly check and truncate 
node->id to INT_MAX (probably with some degree of warning) here just in 
case.

Cheers,
Robin.

>   	if (!pdev)
>   		return -ENOMEM;
>