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Message-ID: <bfa921830db255b901b0bb586b090846466a8ab0.camel@linux.intel.com>
Subject: Re: [PATCH] HID: sensor-hub: Enable hid core report processing for
 all devices
From: srinivas pandruvada <srinivas.pandruvada@linux.intel.com>
To: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Yauhen Kharuzhy <jekhor@gmail.com>, Jonathan Cameron <jic23@kernel.org>,
  linux-input@vger.kernel.org, linux-iio@vger.kernel.org, Daniel Thompson
 <daniel.thompson@linaro.org>, linux-kernel@vger.kernel.org, Jiri Kosina
 <jikos@kernel.org>
Date: Fri, 22 Dec 2023 06:24:45 -0800
In-Reply-To: <CAO-hwJ+RDnukVhL1=PirK=hU7gm2t73xsg=aDss0M9hj_CSuHA@mail.gmail.com>
References: <20231219231503.1506801-1-jekhor@gmail.com>
	 <20231220145229.020abe62@jic23-huawei>
	 <CAKWEGV50duj-TcKdQp1BtN_QgnBZyG0WgAqo8Y5UtCinqOAh_g@mail.gmail.com>
	 <38313826939a468ff8c7eee24e2cf07e9eef6768.camel@linux.intel.com>
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On Fri, 2023-12-22 at 14:28 +0100, Benjamin Tissoires wrote:
> On Fri, Dec 22, 2023 at 1:44=E2=80=AFPM srinivas pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
> >=20
> > On Wed, 2023-12-20 at 17:04 +0200, Yauhen Kharuzhy wrote:
> > > =D1=81=D1=80, 20 =D0=B4=D0=B5=D0=BA. 2023=E2=80=AF=D0=B3. =D0=B2 16:5=
2, Jonathan Cameron <jic23@kernel.org>:
> > > >=20
> > > > On Wed, 20 Dec 2023 01:15:03 +0200
> > > > Yauhen Kharuzhy <jekhor@gmail.com> wrote:
> > > >=20
> > > > > After the commit 666cf30a589a ("HID: sensor-hub: Allow multi-
> > > > > function
> > > > > sensor devices") hub devices are claimed by hidraw driver in
> > > > > hid_connect().
> > > > > This causes stoppping of processing HID reports by hid core
> > > > > due
> > > > > to
> > > > > optimization.
> > > > >=20
> > > > > In such case, the hid-sensor-custom driver cannot match a
> > > > > known
> > > > > custom
> > > > > sensor in hid_sensor_custom_get_known() because it try to
> > > > > check
> > > > > custom
> > > > > properties which weren't filled from the report because hid
> > > > > core
> > > > > didn't
> > > > > parsed it.
> > > > >=20
> > > > > As result, custom sensors like hinge angle sensor and LISS
> > > > > sensors
> > > > > don't work.
> > > > >=20
> > > > > Mark the sensor hub devices claimed by some driver to avoid
> > > > > hidraw-related
> > > > > optimizations.
> > > > >=20
> > > > > Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
> > > > Fixes tag?
> > >=20
> > > Fixes: 666cf30a589a ("HID: sensor-hub: Allow multi-function
> > > sensor
> > > devices")
> > >=20
> > This flag causes
> > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0 hdev->claimed |=3D HID_CLAIMED_DRIVER;
> > I don't see the flag is used anywhere after this assignment in hid
> > core. Only two other drivers are setting this flag. We need Jiri's
> > help
> > here why this is a special case.
>=20
> It's used in hid_report_raw_event()[0]:
> ```
> =C2=A0=C2=A0=C2=A0 if (hid->claimed !=3D HID_CLAIMED_HIDRAW && report->ma=
xfield) {
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 hid_process_report(hid, report=
, cdata, interrupt);
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 hdrv =3D hid->driver;
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (hdrv && hdrv->report)
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 hdrv->=
report(hid, report);
> =C2=A0=C2=A0=C2=A0 }
> ```
>=20
> The whole point of setting HID_CLAIMED_DRIVER is to have hid->claimed
> not equal to HID_CLAIMED_HIDRAW, in case we need the hid core
> processing.
Thanks Benjamin for explaining.
Then this change looks fine as sensor hub driver will claim this device
and it needs hid core to process report.

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Thanks,
Srinivas

>=20
> Cheers,
> Benjamin
>=20
>=20
> [0]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/d=
rivers/hid/hid-core.c#n2015
>=20
> >=20
> > Thanks,
> > Srinivas
> >=20
> > > >=20
> > > > > ---
> > > > > =C2=A0drivers/hid/hid-sensor-hub.c | 2 +-
> > > > > =C2=A01 file changed, 1 insertion(+), 1 deletion(-)
> > > > >=20
> > > > > diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-
> > > > > sensor-hub.c
> > > > > index 2eba152e8b90..26e93a331a51 100644
> > > > > --- a/drivers/hid/hid-sensor-hub.c
> > > > > +++ b/drivers/hid/hid-sensor-hub.c
> > > > > @@ -632,7 +632,7 @@ static int sensor_hub_probe(struct
> > > > > hid_device
> > > > > *hdev,
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 }
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 INIT_LIST_HEAD(&hdev->inputs);
> > > > >=20
> > > > > -=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D hid_hw_start(hdev, HID_CONNECT_=
DEFAULT);
> > > > > +=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D hid_hw_start(hdev, HID_CONNECT_=
DEFAULT |
> > > > > HID_CONNECT_DRIVER);
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (ret) {
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0 hid_err(hdev, "hw start failed\n");
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0 return ret;
> > > >=20
> > >=20
> > >=20
> >=20
>=20