Re: [PATCH 3/3] platform/x86/amd: hfi: Rely on ACPI enumeration instead of a dummy device

[Mario Limonciello <mario.limonciello@amd.com>]

On 9/21/26 12:04, Mario Limonciello wrote:
> amd_hfi_init() manually registers a platform device with
> platform_device_register_simple() before registering the driver.  This
> device has no ACPI companion, so when amd_hfi_probe() runs for it the
> acpi_match_device() check fails and probe returns -ENODEV.
> 
> The driver already advertises an ACPI match table, so the ACPI subsystem
> enumerates the real AMDI0104 device and binds it to the driver.  The
> manually created device therefore serves no purpose: it never binds and
> lingers as an unbound platform device, wasting memory and cluttering the
> device tree.
> 
> Drop the manual platform_device_register_simple() and the device that
> tracked it, and rely solely on ACPI enumeration.  The CPU feature gating
> in amd_hfi_init() is retained so the driver is only registered on
> supported hardware.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: 
https://sashiko.dev/#/bug/linux-8791990d-979b-4901-81b0-a8c6fdb67c7a> ---
>   drivers/platform/x86/amd/hfi/hfi.c | 9 ---------
>   1 file changed, 9 deletions(-)
> 
> diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c
> index 6d1d3b6c28a97..a923345dd1cf6 100644
> --- a/drivers/platform/x86/amd/hfi/hfi.c
> +++ b/drivers/platform/x86/amd/hfi/hfi.c
> @@ -39,8 +39,6 @@
>   
>   #define AMD_HETERO_CPUID_27	0x80000027
>   
> -static struct platform_device *device;
> -
>   /**
>    * struct amd_shmem_info - Shared memory table for AMD HFI
>    *
> @@ -540,12 +538,6 @@ static int __init amd_hfi_init(void)
>   	    !cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS))
>   		return -ENODEV;
>   
> -	device = platform_device_register_simple(AMD_HFI_DRIVER, -1, NULL, 0);
> -	if (IS_ERR(device)) {
> -		pr_err("unable to register HFI platform device\n");
> -		return PTR_ERR(device);
> -	}
> -
>   	ret = platform_driver_register(&amd_hfi_driver);
>   	if (ret)
>   		pr_err("failed to register HFI driver\n");
> @@ -556,7 +548,6 @@ static int __init amd_hfi_init(void)
>   static __exit void amd_hfi_exit(void)
>   {
>   	platform_driver_unregister(&amd_hfi_driver);
> -	platform_device_unregister(device);
>   }
>   module_init(amd_hfi_init);
>   module_exit(amd_hfi_exit);