Re: Problem: ACPI related soft lockup on Fujitsu-Siemens AMILO Si 2636

[Thomas Renninger <trenn@suse.de>]

On Wednesday 08 October 2008 12:48:36 Thomas Lindroth wrote:
> Alexey Starikovskiy wrote:
> > Alexey Starikovskiy wrote:
> >> This is AML implementation of EC driver... it relies on certain speed
> >> of AML interpreter to work properly (look for Noop inserted as delay).
> >>
> >> It is possible to replace this driver with the native Linux one, which
> >> might be
> >> more robust, but this involves heavy DSDT hacking.
> >>
> >> Overall, it is heavily mis-designed BIOS, so don't expect it to be
> >> fixed on Linux side.
> >>
> >> Regards,
> >> Alex.
> >
> > Please check if making Noop a small delay helps
>
> I've tried the patch with an udelay of 100 but it did not make any
> difference. I've also tried raising it to 200 but that created an
> unbootable system because one of the ACPI init methods failed.
>
> You are right, this is a really broken BIOS.
>
> I find it odd that only I experience this problem. According to one
> site this laptop is the 7:th most popular laptop right now so someone
> else should have reported something.

Could you provide a short explanation what should be fixed in which way in the 
BIOS tables. Best in a way that I can just forward this.
It's hard in the laptop area to convince fsc to fix it, but I at least like to 
try and to tell them.
Hmm, I think the last two mails should already be enough, I think  I got it.

Is there a general hint I could add into the ACPI Linux guideline, like:
Don't implement EC data/index register reads/writes in AML yourself.
Define a EC variable and e.g. use Store(ECXY, Local0) to read and
Store(Local0, ECXY) to write to specific EC bytes.

Did I get this right?

Thanks,

     Thomas