Re: [PATCH] gpiolib: acpi: Support GpioInt with active_low polarity

From: Andy Shevchenko
Date: Thu Oct 29 2020 - 13:31:39 EST


On Thu, Oct 29, 2020 at 5:37 PM Ricardo Ribalda <ribalda@xxxxxxxxxx> wrote:
> On Thu, Oct 29, 2020 at 3:38 PM Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> >
> > On Wed, Oct 28, 2020 at 06:17:57PM +0100, Ricardo Ribalda wrote:
> > > On the current implementation we only support active_high polarity for
> > > GpioInt.
> > >
> > > There can be cases where a GPIO has active_low polarity and it is also a
> > > IRQ source.
> > >
> > > De-couple the irq_polarity and active_low fields instead of re-use it.
> > >
> > > With this patch we support ACPI devices such as:
> >
> > Is it real device on the market?!
>
> Yes, it is a chromebook.

You mean it's already on sale with this broken table?!

> > This table is broken. _DSD GPIO active_low is only for GpioIo().
>
> AFAIK the format of the _DSD is not in the ACPI standard. We have
> decided its fields. (please correct me if I am wrong here)

_DSD is a concept that is part of the spec, but each UUID and its
application is out of scope indeed.

GPIO application to _DSD is described in the in-kernel documentation.
Thanks for pointing out the issues it has.

> On the other mail I have described why we need to make use of the
> active_low on a GpioInt()
>
> If there is another way of describing ActiveBoth + inverted polarity
> please let me know and I will go that way.

I answered it there, please, continue this topic there.
NAK to the proposed change.

> > If it is a ChromeBook, please fix the firmware.

--
With Best Regards,
Andy Shevchenko