RE: [PATCH] ACPI / EC: handle ECDT EC and DSDT EC simultaneously

["Zheng, Lv" <lv.zheng@intel.com>]

Hi, Daniel

> From: Daniel Drake [mailto:drake@endlessm.com]
> Subject: Re: [PATCH] ACPI / EC: handle ECDT EC and DSDT EC simultaneously
> 
> On Thu, Apr 27, 2017 at 6:33 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> > Can you suggest a patch, please?
> >
> > Ideally, something that can be tested?
> 
> I think I understand Lv's suggestions so we will now test the
> following change in order to check if either or both of the added DSDT
> EC checks can help us.
> 
> https://gist.github.com/dsd/f50a63c9f31779436bd280c76253e37c

We did have a good talk, and left good engineering materials in community around this issue.

However in the above debugging commit, I'm sure we shouldn't invoke _STA in ec_parse_device().
As the reasons below.

In theory, using DSDT EC as boot EC is not spec compliant.
It's just a workaround in Linux for not knowing the Windows device enumeration orders.
Especially, the order of executing the control method execution that may contain hardware initialization code.
Such control methods are mostly _STA/_INI.
While for _HID/_CRS/_GPE/_BBN, it is unlikely to trigger order issues and it might be safe to invoke them such early.

If you executes _STA here, you might bring EC._STA execution prior than other _INI/_STA and may break some other platforms.
So for now, I think you should only add simple sanity checks for ioports.
And since you have the direct accesses to these affected platforms, you can help to provide such working sanity check improvements for us.

Thanks and best regards
Lv