Re: [PATCH v11 2/6] gpiolib: allow to specify the firmware node in struct gpio_chip

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Kent Gibson <warthog618@gmail.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Shuah Khan <shuah@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v11 2/6] gpiolib: allow to specify the firmware node in struct gpio_chip
Date: Wed, 1 Dec 2021 16:33:27 +0200	[thread overview]
Message-ID: <YaeHtzyqe3XwgWw/@smile.fi.intel.com> (raw)
In-Reply-To: <YaeGg34Log9dExYX@smile.fi.intel.com>

On Wed, Dec 01, 2021 at 04:28:19PM +0200, Andy Shevchenko wrote:
> On Wed, Dec 01, 2021 at 02:53:42PM +0100, Bartosz Golaszewski wrote:
> > On Wed, Dec 1, 2021 at 2:40 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Wed, Dec 01, 2021 at 02:11:28PM +0100, Bartosz Golaszewski wrote:
> > > > On Tue, Nov 30, 2021 at 10:04 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> 
> ...
> 
> > > > Let me maybe rephrase the problem: currently, for GPIO devices
> > > > instantiating multiple banks created outside of the OF or ACPI
> > > > frameworks (e.g. instantiated manually and configured using a
> > > > hierarchy of software nodes with a single parent swnode and a number
> > > > of child swnodes representing the children), it is impossible to
> > > > assign firmware nodes other than the one representing the top GPIO
> > > > device to the gpiochip child devices.
> > > >
> > > > In fact if we want to drop the OF APIs entirely from gpiolib - this
> > > > would be the right first step as for gpio-sim it actually replaces the
> > > > gc->of_node = some_of_node; assignment that OF-based drivers do for
> > > > sub-nodes defining banks and it does work with device-tree (I verified
> > > > that too) thanks to the fwnode abstraction layer.
> > >
> > > I still don't see how you set up hierarchy of primary/secondary fwnodes.
> > >
> > > And I don't like this change. It seems it band-aids some issue with fwnode
> > > usage. What the easiest way to reproduce the issue with your series applied
> > > (without this change)?
> > 
> > Drop this patch and drop the line where the fwnode is assigned in
> > gpio-sim.c. Then probe the device and print the addresses of the
> > parent and child swnodes. See how they are the same and don't match
> > the swnode hierarchy we created. You can then apply this patch and see
> > how it becomes correct.
> 
> Thanks. I will give a spin.
> 
> Note, it seems I have to revert your older code first...

Okay, I have to postpone because simple revert doesn't work for me.
Can you clean up the next, please and I can use it starting from tomorrow?

$ git tag --contains 5065e08e4ef3
DONT-USE-next-20211105
next-20211101
next-20211102
next-20211103
next-20211104
next-20211105
next-20211106
next-20211108
next-20211109
next-20211110
next-20211111
next-20211112
next-20211115
next-20211116
next-20211117
next-20211118
next-20211123
next-20211124
next-20211125
next-20211126
next-20211129
next-20211130
next-20211201

-- 
With Best Regards,
Andy Shevchenko