Received-SPF: pass (google.com: domain of linux-kernel+bounces-1276-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Fri, 15 Dec 2023 16:15:39 +0000
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
CC: "Rafael J. Wysocki" <rafael@kernel.org>, <linux-pm@vger.kernel.org>,
	<loongarch@lists.linux.dev>, <linux-acpi@vger.kernel.org>,
	<linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <linux-riscv@lists.infradead.org>,
	<kvmarm@lists.linux.dev>, <x86@kernel.org>,
	<acpica-devel@lists.linuxfoundation.org>, <linux-csky@vger.kernel.org>,
	<linux-doc@vger.kernel.org>, <linux-ia64@vger.kernel.org>,
	<linux-parisc@vger.kernel.org>, Salil Mehta <salil.mehta@huawei.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>, <jianyong.wu@arm.com>,
	<justin.he@arm.com>, James Morse <james.morse@arm.com>
Subject: Re: [PATCH RFC v3 01/21] ACPI: Only enumerate enabled (or
 functional) devices
Message-ID: <20231215161539.00000940@Huawei.com>
In-Reply-To: <ZXxxa+XZjPZtNfJ+@shell.armlinux.org.uk>
References: <ZXmn46ptis59F0CO@shell.armlinux.org.uk>
	<E1rDOfs-00DvjY-HQ@rmk-PC.armlinux.org.uk>
	<20231214173241.0000260f@Huawei.com>
	<CAJZ5v0jymOtZ0y65K9wE8FJk+ZKwP+FoGm4AKHXcYVfQJL9MVw@mail.gmail.com>
	<ZXtFBYJEX2RrFrwj@shell.armlinux.org.uk>
	<CAJZ5v0h2Keyb-gFWFuPsKtwqjXvM2snyGpo6MMfFzaXKbfEpgw@mail.gmail.com>
	<CAJZ5v0h3WWtvrbxRpaGfq6c756k+L1SzZ1Gv3A14JxXHNcUMKA@mail.gmail.com>
	<ZXxxa+XZjPZtNfJ+@shell.armlinux.org.uk>
Organization: Huawei Technologies Research and Development (UK) Ltd.
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable

On Fri, 15 Dec 2023 15:31:55 +0000
"Russell King (Oracle)" <linux@armlinux.org.uk> wrote:

> On Thu, Dec 14, 2023 at 07:37:10PM +0100, Rafael J. Wysocki wrote:
> > On Thu, Dec 14, 2023 at 7:16=E2=80=AFPM Rafael J. Wysocki <rafael@kerne=
l.org> wrote: =20
> > >
> > > On Thu, Dec 14, 2023 at 7:10=E2=80=AFPM Russell King (Oracle)
> > > <linux@armlinux.org.uk> wrote: =20
> > > > I guess we need something like:
> > > >
> > > >         if (device->status.present)
> > > >                 return device->device_type !=3D ACPI_BUS_TYPE_PROCE=
SSOR ||
> > > >                        device->status.enabled;
> > > >         else
> > > >                 return device->status.functional;
> > > >
> > > > so we only check device->status.enabled for processor-type devices?=
 =20
> > >
> > > Yes, something like this. =20
> >=20
> > However, that is not sufficient, because there are
> > ACPI_BUS_TYPE_DEVICE devices representing processors.
> >=20
> > I'm not sure about a clean way to do it ATM. =20
>=20
> Ok, how about:
>=20
> static bool acpi_dev_is_processor(const struct acpi_device *device)
> {
> 	struct acpi_hardware_id *hwid;
>=20
> 	if (device->device_type =3D=3D ACPI_BUS_TYPE_PROCESSOR)
> 		return true;
>=20
> 	if (device->device_type !=3D ACPI_BUS_TYPE_DEVICE)
> 		return false;
>=20
> 	list_for_each_entry(hwid, &device->pnp.ids, list)
> 		if (!strcmp(ACPI_PROCESSOR_OBJECT_HID, hwid->id) ||
> 		    !strcmp(ACPI_PROCESSOR_DEVICE_HID, hwid->id))
> 			return true;
>=20
> 	return false;
> }
>=20
> and then:
>=20
> 	if (device->status.present)
> 		return !acpi_dev_is_processor(device) || device->status.enabled;
> 	else
> 		return device->status.functional;
>=20
> ?
>=20
Changing it to CPU only for now makes sense to me and I think this code sni=
ppet should do the
job.  Nice and simple.