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

[Akihiko Odaki]

On 2022/06/28 23:42, Limonciello, Mario wrote:
> 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.

Yes. I confirmed it with 78ca55889a549a9a194c6ec666836329b774ab6d.

b5d7f43e97dabfa04a4be5ff027ce7da119332be deals with the case where it 
advertises v2 but it doesn't in my case.

Regards,
Akihiko Odaki

> > Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxx>
> > ---
> >   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) {