Re: [PATCH 1/2] gpio / CrystalCove: support virtual GPIO

Linus Walleij
2014-09-23T10:13:56Z

On Tue, Sep 9, 2014 at 4:32 AM, Aaron Lu <aaron.lu@intel.com> wrote:

> The virtual GPIO introduced in ACPI table of Baytrail-T based system is
> used to solve a problem under Windows. We do not have such problems
> under Linux so we do not actually need them. But we have to tell GPIO
> library that the Crystal Cove GPIO chip has this many GPIO pins or the
> common GPIO handler will refuse any access to those high number GPIO
> pins, which will resulted in a failure evaluation of every ACPI control
> method that is used to turn on/off power resource and/or report sensor
> temperatures.
>
> Due to the high number of virtual GPIOs, the value of ARCH_NR_GPIOS is
> bumped from 256 to 512 to avoid failures on platforms that have various
> GPIO controllers.
>
> Signed-off-by: Aaron Lu <aaron.lu@intel.com>

I have some other patch pending increasing the default GPIO# to
512, but anyhow: this needs review from someone. Where is
Lejun? Mika also reviewed last time. Someone I trust to understand
ACPI need to be involved, Rafael, Darren....

Yours,
Linus Walleij