Re: [PATCH v2 2/4] pinctrl: samsung: Register pinctrl before GPIO

From: Linus Walleij <linus.walleij@linaro.org>
To: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	linux-samsung-soc <linux-samsung-soc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"open list:WOLFSON MICROELECTRONICS DRIVERS"
	<patches@opensource.wolfsonmicro.com>
Subject: Re: [PATCH v2 2/4] pinctrl: samsung: Register pinctrl before GPIO
Date: Tue, 14 Mar 2017 14:44:15 +0100	[thread overview]
Message-ID: <CACRpkdZ+EQ=p_vGrBFYu6p-MnC0OvcY7P1-OWzebKgQRhGWQJQ@mail.gmail.com> (raw)
In-Reply-To: <20170223172313.GF2742@localhost.localdomain>

On Thu, Feb 23, 2017 at 6:23 PM, Charles Keepax
<ckeepax@opensource.wolfsonmicro.com> wrote:
> On Wed, Feb 22, 2017 at 03:37:37PM +0100, Linus Walleij wrote:
>> On Thu, Feb 16, 2017 at 2:27 PM, Charles Keepax
>> <ckeepax@opensource.wolfsonmicro.com> wrote:
>>
>> > If we request a GPIO hog, then gpiochip_add_data will attempt to request
>> > some of its own GPIOs. The driver also uses gpiochip_generic_request
>> > which means that for any GPIO request to succeed the pinctrl needs to be
>> > registered. Currently however the driver registers the GPIO and then the
>> > pinctrl meaning all GPIO hog requests will fail, which then in turn causes
>> > the whole driver to fail probe. Fix this up by ensuring we register the
>> > pinctrl first. Although currently there are no users of GPIO hogs in
>> > mainline there are plenty of Samsung based boards that are widely used
>> > for development purposes of other hardware. Indeed we hit this issue
>> > whilst attaching some additional hardware to an Arndale system.
>> >
>> > Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
>> > Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
>> > ---
>> >
>> > Changes since v1:
>> >  - Updated commit message
>>
>> Patch applied. Will not be visible in -next until after the merge window
>> though.
>>
>
> Apologies but I think you might be best to drop this patch for
> now, it seems this causes the ranges passed to
> pinctrl_add_gpio_range to have the wrong .base, whilst I can
> actually see no ill effects from this on Arndale. I suspect this
> patch may be only part of the solution and may potentially cause
> issues for others even though it seems fine for me.

OK I dropped it.

Resend it if you figure it out.

The Samsung driver traffic is increasing, and there are now
a bunch of developers starting to step on each others' toes.

Would you Samsung developers start considering someone who
can collect Samsung pin control patches and send them as
pull requests to me?

Yours,
Linus Walleij