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

On Thu, 9 Jul 2026, Robin Murphy wrote:

On 09/07/2026 3:39 pm, Robin Murphy wrote:

quoted

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.

That's a good idea.

quoted

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.

Yeah, it probably and hopefully won't happen but it makes sense to have a 
warning message regardless. With it

Reviewed-by: Ilkka Koskinen <redacted>

Cheers, Ilkka

Cheers,
Robin.

quoted

  	if (!pdev)
  		return -ENOMEM;