[PATCH RFC 1/4] ARM: bcm2835: remove sdhci pins from GPIO pinctrl

[Stefan Wahren]

> Stephen Warren <swarren at wwwdotorg.org> hat am 2. Dezember 2015 um 04:40
> geschrieben:
>
>
> On 11/19/2015 09:06 AM, Stefan Wahren wrote:
> > Currently the pins alt3 (sdhci) are assigned to GPIO pinctrl.
> > This is bad because a user could export it to sysfs and break
> > sdhci. In order to avoid that remove those pins from GPIO pintrl.
>
> > diff --git a/arch/arm/boot/dts/bcm2835-rpi-a-plus.dts
> > b/arch/arm/boot/dts/bcm2835-rpi-a-plus.dts
>
> > &gpio {
> > - pinctrl-0 = <&gpioout &alt0 &i2s_alt0 &alt3>;
> > + pinctrl-0 = <&gpioout &alt0 &i2s_alt0>;
>
> This doesn't make sense. The current DT content is configuring those
> pins as SDHCI, not as GPIO. Admitedly this is redundant since the
> firmware and/or bootloader already did this in order to boot the system,
> but irrespective, the current DT causes no issues. Removing the pinctrl
> setting should not influence whether the pins can be exported via GPIO
> sysfs either.

You are right. 

Is it generally possible to avoid the GPIO sysfs export for SDHCI pins? 
Is it an issue of pinctrl-bcm2835?