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From: Greg KH <gregkh@linuxfoundation.org>
To: "Enrico Weigelt, metux IT consult" <info@metux.net>
Cc: linux-kernel@vger.kernel.org, rafael@kernel.org,
	linus.walleij@linaro.org, bgolaszewski@baylibre.com,
	robh+dt@kernel.org, frowand.list@gmail.com,
	pantelis.antoniou@konsulko.com, linux-gpio@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: Re: [RFC PATCH 09/12] drivers: base: reintroduce find_bus()
Date: Wed, 24 Feb 2021 17:28:20 +0100	[thread overview]
Message-ID: <YDZ+pEY3vJZ+GsvO@kroah.com> (raw)
In-Reply-To: <9db34ee4-30dc-9e69-6e82-00cbf4615ed5@metux.net>

On Wed, Feb 24, 2021 at 04:30:42PM +0100, Enrico Weigelt, metux IT consult wrote:
> On 24.02.21 09:00, Greg KH wrote:
> 
> > Have the firmware code do it itself, do nto try to "reach across" like
> > this.
> 
> By "firmware code" you mean Linux acpi core or the board's bios ?

either.

> a) Fixing BIOS would be the cleanest solution, but we cant expect all
>    users to do field upgrades. Many of the devices (eg. the customer,
>    I've originally wrote the apu board driver for, deployed them in
>    really remote locations, sometimes even just reachable by ship,
>    heli or horse, litterally)
> 
> b) Explicit blacklisting somewhere in apci enumeration code could work,
>    but I really hate the idea of such board and bios version specific
>    quirks in a place, completely unrelated to the actual board driver.

We have quirks all over the place, that's normal and how we handle
broken hardware/bios al the time.

> Actually, I'm also hoping to find a proper way for having those things
> in one file per board, in the future. (probably not applicable for
> early stuff, or _OSI(Linux), etc)

I don't know what "things" you are referring to here at all.

> > And what problem are you really trying to solve here by doing this?
> 
> The problem is that *some* bios versions (that came much later, after
> pcengines-apuv2 driver went into production) added a few things that
> the driver is already doing - different versions doing it differently
> (eg. even enumerating gpio connected leds with completely different
> names, etc), and still some gpio connected devices missing. Some
> versions (just forgot, which one it's been exactly) even enumerate
> *some* gpios (and LEDs behind them) as a different device, whose Linux
> driver just happens to work. Meanwhile I can't find any reference of
> that in the coreboot source, anymore.

I have no idea what you are talking about here, you did not describe a
problem :(

> As you can see: bios is anything but reliable on that platform.

I do not understand.

> What I'm trying to achieve: the kernel should behave exactly the
> same, no matter what board revision, bios version, kernel version,
> etc. (there should be especially no need to have special per-board
> quirks in userland, depending on board rev, bios version, kernel
> version).
> 
> If you've got a better solution, I'll be glad to hear it.

I really do not understand the problem, sorry.

greg k-h

  reply	other threads:[~2021-02-24 16:32 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-08 22:21 RFC: oftree based setup of composite board devices Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 01/12] of: base: improve error message in of_phandle_iterator_next() Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 02/12] of: base: introduce of_find_node_by_phandle_from() Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 03/12] of: base: record root node in interator and use it for phandle lookup Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 04/12] of: base: introduce of_match_string() Enrico Weigelt, metux IT consult
2021-02-08 23:52   ` Rob Herring
2021-02-08 22:21 ` [RFC PATCH 05/12] of: kobj: __of_attach_node_sysfs(): add optional basename parameter Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 06/12] of: kobj: introduce of_attach_tree_sysfs() Enrico Weigelt, metux IT consult
2021-02-08 22:21 ` [RFC PATCH 07/12] gpio: amd-fch: add oftree probing support Enrico Weigelt, metux IT consult
2021-02-11  9:57   ` Bartosz Golaszewski
2021-03-01 14:51   ` Linus Walleij
2021-03-11 10:17     ` Enrico Weigelt, metux IT consult
2021-03-11 10:42       ` Andy Shevchenko
2021-03-18  8:00         ` Enrico Weigelt, metux IT consult
2021-03-25  9:09           ` Linus Walleij
2021-02-08 22:21 ` [RFC PATCH 08/12] drivers: base: introduce bus_remove_device_by_name() Enrico Weigelt, metux IT consult
2021-02-08 22:22 ` [RFC PATCH 09/12] drivers: base: reintroduce find_bus() Enrico Weigelt, metux IT consult
2021-02-13 10:20   ` Greg KH
2021-02-23 20:13     ` Enrico Weigelt, metux IT consult
2021-02-24  8:00       ` Greg KH
2021-02-24 15:30         ` Enrico Weigelt, metux IT consult
2021-02-24 16:28           ` Greg KH [this message]
2021-02-08 22:22 ` [RFC PATCH 10/12] export bus_get() / bus_put() Enrico Weigelt, metux IT consult
2021-02-08 22:22 ` [RFC PATCH 11/12] platform/x86: skeleton for oftree based board device initialization Enrico Weigelt, metux IT consult
2021-02-10 10:32   ` Andy Shevchenko
2021-02-12  9:58   ` Linus Walleij
2021-02-12 11:54     ` Enrico Weigelt, metux IT consult
2021-02-15  1:18       ` Frank Rowand
2021-02-23 20:41         ` Enrico Weigelt, metux IT consult
2021-03-02 13:33       ` Linus Walleij
2021-02-08 22:22 ` [RFC PATCH 12/12] platform/x86/of: add support for PC Engines APU v2/3/4 boards Enrico Weigelt, metux IT consult
2021-02-09  0:06   ` Rob Herring
2021-02-11 13:15     ` Enrico Weigelt, metux IT consult
2021-03-01 14:55   ` Linus Walleij
2021-02-08 23:48 ` RFC: oftree based setup of composite board devices Rob Herring
2021-02-10 22:13   ` Enrico Weigelt, metux IT consult
2021-02-15  1:12   ` Frank Rowand
2021-02-15 15:35     ` Andy Shevchenko
2021-02-24 13:00     ` Enrico Weigelt, metux IT consult
2021-02-24 23:14       ` Frank Rowand
2021-03-05 18:29         ` Rob Herring
2021-02-10 10:30 ` Andy Shevchenko
2021-02-11 11:08   ` Enrico Weigelt, metux IT consult
2021-02-11 11:41     ` Andy Shevchenko
2021-02-11 17:01       ` Enrico Weigelt, metux IT consult

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