Re: [PATCH] HID: amd_sfh: Ignore uninitialized device

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

On 6/26/2022 03:13, Akihiko Odaki wrote:
> Lenovo ThinkPad C13 Yoga has AMD Sensor Fusion Hub, but it is not used
> because Chrome OS EC Sensor Hub is used instead. The system therefore
> never loads the firmware for MP2 and MP2 does not work. It results in
> AMD_P2C_MSG3 register to have -1 as its value.
> 
> Without this change, the driver interprets the value as it supports all
> sensor types and exposes them, which confuses a userspace program,
> iio-sensor-proxy, and makes it to use the non-functioning sensors
> instead of functioning sensors exposed via Chrome OS EC Sensor Hub.
> 
> Check the version bits included in AMD_P2C_MSG3 register and ignore the
> device if all of the bits are set.
> 

Have you already confirmed this failure happens in 5.19-rc1 or later as 
well?  I would think that b5d7f43e97dabfa04a4be5ff027ce7da119332be 
should have fixed it.

> Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
> ---
>   drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> index dadc491bbf6b..4137e5da77ad 100644
> --- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> +++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> @@ -271,6 +271,8 @@ static void mp2_select_ops(struct amd_mp2_dev *privdata)
>   	case V2_STATUS:
>   		privdata->mp2_ops = &amd_sfh_ops_v2;
>   		break;
> +	case 15:
> +		break;
>   	default:
>   		privdata->mp2_ops = &amd_sfh_ops;
>   		break;
> @@ -317,6 +319,8 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i
>   		return -ENOMEM;
>   
>   	mp2_select_ops(privdata);
> +	if (!privdata->mp2_ops)
> +		return -ENODEV;
>   
>   	rc = amd_sfh_irq_init(privdata);
>   	if (rc) {