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From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Henning Schild <henning.schild@siemens.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Jean Delvare <jdelvare@suse.de>, Lee Jones <lee.jones@linaro.org>,
	Tan Jui Nee <jui.nee.tan@intel.com>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	Jonathan Yong <jonathan.yong@intel.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-i2c <linux-i2c@vger.kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>,
	Jean Delvare <jdelvare@suse.com>,
	Peter Tyser <ptyser@xes-inc.com>,
	Hans de Goede <hdegoede@redhat.com>
Subject: Re: [rfc, PATCH v1 0/7] PCI: introduce p2sb helper
Date: Thu, 10 Jun 2021 13:14:49 +0300	[thread overview]
Message-ID: <CAHp75VeYy0tyP-OLZX5dbYFZM1C_K5eALo64_nb4rSvH7-93FA@mail.gmail.com> (raw)
In-Reply-To: <20210610110211.0e239af6@md1za8fc.ad001.siemens.net>

On Thu, Jun 10, 2021 at 12:14 PM Henning Schild
<henning.schild@siemens.com> wrote:
>
> Am Mon, 8 Mar 2021 14:20:13 +0200
> schrieb Andy Shevchenko <andriy.shevchenko@linux.intel.com>:
>
> > There are a few users and even at least one more is coming
> > that would like to utilize p2sb mechanisms like hide/unhide
> > a device from PCI configuration space.
> >
> > Here is the series to deduplicate existing users and provide
> > a generic way for new comers.
> >
> > It also includes a patch to enable GPIO controllers on Apollo Lake
> > when it's used with ABL bootloader w/o ACPI support.
>
> That bit is especially interesting. Making pinctl*lake initialize when
> ACPI IDs are missing and p2sb is hidden.
>
> However i have seen pinctl-broxton get confused because it was trying
> to come up twice on a system that has the ACPI entries. Once as
> "INT3452" and second as "apollolake-pinctrl". They should probably
> mutually exclude each other. And the two different names for "the
> same"? thing make it impossible to write a driver using those GPIOs.

Then it's clearly told that BIOS provides confusing data, it exposes
the ACPI device and hides it in p2sb, how is it even supposed to work?

I consider only these are valid:
 - ACPI device is provided and it's enabled (status = 15) => work with
ACPI enumeration
 - no ACPI device provided and it's hidden or not by p2sb => work via board file
 - no ACPI device provided and no device needed / present => no driver is needed

> Unless it would try and look up both variants or not looking up with
> gpiochip.label.
>
> I would also need that "enable GPIO w/o ACPI" for skylake.

Not a problem to add a platform driver name there or actually for all
of the Intel pin control drivers (depends what suits better to the
current design).

>  I think it
> would be generally useful if the GPIO controllers would be enabled not
> depending on ACPI, and coming up with only one "label" to build on top.

I didn't get what 'label' means here...

> > Please, comment on the approach and individual patches.
> >
> > (Since it's cross subsystem, the PCI seems like a main one and
> >  I think it makes sense to route it thru it with immutable tag
> >  or branch provided for the others).


-- 
With Best Regards,
Andy Shevchenko

  reply	other threads:[~2021-06-10 10:16 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-08 12:20 [rfc, PATCH v1 0/7] PCI: introduce p2sb helper Andy Shevchenko
2021-03-08 12:20 ` [PATCH v1 1/7] PCI: Introduce pci_bus_*() printing macros when device is not available Andy Shevchenko
2021-03-10 14:57   ` Jean Delvare
2021-03-08 12:20 ` [PATCH v1 2/7] PCI: Convert __pci_read_base() to __pci_bus_read_base() Andy Shevchenko
2021-03-10 17:14   ` Christoph Hellwig
2021-03-08 12:20 ` [PATCH v1 3/7] PCI: New Primary to Sideband (P2SB) bridge support library Andy Shevchenko
2021-03-08 18:52   ` Bjorn Helgaas
2021-03-08 19:16     ` Andy Shevchenko
2021-03-09  1:42       ` Bjorn Helgaas
2021-03-09  8:42         ` Henning Schild
2021-04-01 15:45           ` Andy Shevchenko
2021-04-01 16:42             ` Bjorn Helgaas
2021-04-01 18:23               ` Andy Shevchenko
2021-04-01 18:44                 ` Bjorn Helgaas
2021-07-12 12:15                   ` Andy Shevchenko
2021-11-26 15:10                     ` Andy Shevchenko
2021-04-02 13:09           ` Enrico Weigelt, metux IT consult
2021-04-06 13:40             ` Henning Schild
2021-07-12 12:11               ` Andy Shevchenko
2021-11-26 15:38         ` Andy Shevchenko
2021-11-29 21:07           ` Bjorn Helgaas
2021-12-08 17:51             ` Andy Shevchenko
2021-03-13  9:45   ` Henning Schild
2021-04-01 15:43     ` Andy Shevchenko
2021-04-01 18:06       ` Mika Westerberg
2021-04-01 18:22         ` Andy Shevchenko
2021-04-01 18:32           ` Mika Westerberg
2021-07-12 12:13             ` Andy Shevchenko
2021-03-08 12:20 ` [PATCH v1 4/7] mfd: lpc_ich: Factor out lpc_ich_enable_spi_write() Andy Shevchenko
2021-03-10 10:29   ` Lee Jones
2021-03-08 12:20 ` [PATCH v1 5/7] mfd: lpc_ich: Switch to generic pci_p2sb_bar() Andy Shevchenko
2021-03-10 10:35   ` Lee Jones
2021-03-10 12:05     ` Andy Shevchenko
2021-03-10 12:57       ` Lee Jones
2021-03-08 12:20 ` [PATCH v1 6/7] mfd: lpc_ich: Add support for pinctrl in non-ACPI system Andy Shevchenko
2021-03-10 10:27   ` Lee Jones
2021-04-12 16:01   ` Henning Schild
2021-04-12 16:40     ` Henning Schild
2021-04-12 16:59       ` Andy Shevchenko
2021-04-12 17:16         ` Henning Schild
2021-04-12 17:34           ` Andy Shevchenko
2021-04-13  6:47             ` Henning Schild
2021-04-12 16:51     ` Andy Shevchenko
2021-04-12 17:27       ` Henning Schild
2021-04-12 17:41         ` Andy Shevchenko
2021-03-08 12:20 ` [PATCH v1 7/7] i2c: i801: convert to use common P2SB accessor Andy Shevchenko
2021-03-10 14:51   ` Jean Delvare
2021-12-21 15:08     ` Andy Shevchenko
2021-03-13  9:25 ` [rfc, PATCH v1 0/7] PCI: introduce p2sb helper Henning Schild
2021-06-10  9:02 ` Henning Schild
2021-06-10 10:14   ` Andy Shevchenko [this message]
2021-06-10 13:48     ` Henning Schild
2021-06-10 14:04       ` Andy Shevchenko
2021-11-26 15:43 ` Andy Shevchenko

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