Re: [PATCH v8 1/4] firmware: introduce sysfs driver for QEMU's fw_cfg device

[Michael S. Tsirkin]

On Sun, Feb 21, 2016 at 08:06:17AM -0500, Gabriel L. Somlo wrote:
> > So for all arches which support ACPI, I think this driver
> > should just rely on ACPI.
> 
> There was a discussion about that a few versions ago, and IIRC the
> conclusion was not to expect the firmware to contend for fw_cfg access
> after the guest kernel boots:
> 
> https://lkml.org/lkml/2015/10/5/283

Interesting. Igor wanted to do this again recently ...
I'll think it over and get back to you/list on this.

> (I even had a prototype version doing what you suggested, but per the above
> reference decided to drop it -- which IMHO is for the better, since otherwise
> I'd have had to ifdef between ACPI and non-ACPI versions of the driver --
> see https://lkml.org/lkml/2015/11/4/534 )

I'm not sure I get it - won't you only ifdef the accessor function?

-- 
MST