linux-kernel - Re: [PATCH v1] ACPI: PNP: Introduce list of known non-PNP devices

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Message-ID: <b6c9bbdeea2f9d7f05d2d129a47e8449033d956c.camel@intel.com>
Date:   Wed, 11 Jan 2023 08:02:29 +0000
From:   "Zhang, Rui" <rui.zhang@...el.com>
To:     "rjw@...ysocki.net" <rjw@...ysocki.net>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Chen, Yu C" <yu.c.chen@...el.com>,
        "Zhang, Yang5" <yang5.zhang@...el.com>
Subject: Re: [PATCH v1] ACPI: PNP: Introduce list of known non-PNP devices

CC Zhang Yang who has tested the patch.

On Wed, 2023-01-11 at 07:25 +0000, Zhang, Rui wrote:
> On Tue, 2023-01-10 at 18:58 +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > 
> > In some cases, PNP device IDs from acpi_pnp_device_ids[] are
> > returned
> > by
> > _CID for devices for which matching platform drivers are present in
> > the
> > kernel and should be bound to them.  However, the IDs coming from
> > _CID
> > cause the PNP scan handler to attach to those devices which
> > prevents
> > platform device objects from being created for them.
> > 
> > Address this by introducing a list of known non-PNP device IDs into
> > acpi_pnp.c such that if a device ID is there in that list, it
> > cannot
> > be
> > attached to by the PNP scan handler and add the platform runtime
> > update
> > and telemetry device IDs to that list to start with.
> > 
> > Reported-by: Chen Yu <yu.c.chen@...el.com>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > ---
> >  drivers/acpi/acpi_pnp.c |   14 +++++++++++++-
> >  1 file changed, 13 insertions(+), 1 deletion(-)
> > 
> > Index: linux-pm/drivers/acpi/acpi_pnp.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/acpi_pnp.c
> > +++ linux-pm/drivers/acpi/acpi_pnp.c
> > @@ -348,10 +348,22 @@ static bool acpi_pnp_match(const char *i
> >  	return false;
> >  }
> >  
> > +/*
> > + * If one of the device IDs below is present in the list of device
> > IDs of a
> > + * given ACPI device object, the PNP scan handler will not attach
> > to
> > that
> > + * object, because there is a proper non-PNP driver in the kernel
> > for the
> > + * device represented by it.
> > + */
> > +static const struct acpi_device_id acpi_nonpnp_device_ids[] = {
> > +	{"INTC1080"},
> > +	{"INTC1081"},
> > +	{""},
> > +};
> > +
> >  static int acpi_pnp_attach(struct acpi_device *adev,
> >  			   const struct acpi_device_id *id)
> >  {
> > -	return 1;
> > +	return !!acpi_match_device_ids(adev, acpi_nonpnp_device_ids);
> 
> acpi_match_device_ids() returns True if the id matches, and in this
> case, acpi_pnp_attach() should return false, right?
> 
It is __acpi_match_device() that returns True when matches, and
acpi_match_device_ids() returns 0 in this case.
So this is not a bug, sorry for the noise.

thanks,
rui

> thanks,
> rui
> 
> >  }
> >  
> >  static struct acpi_scan_handler acpi_pnp_handler = {
> > 
> > 
> >