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

[Alexey Starikovskiy <aystarik@gmail.com>]

Thomas Renninger wrote:
> 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.
>>     
T7 is not very popular setting :)
> 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.
>
>   
As I understand, this is not FSC, but FIC outsource. There is exactly
same thing happening in new FIC laptop.
> 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.
>
>   
Declare EC interface might be a better wording.
> Did I get this right?
>
>   
Yes.
My understanding is that Windows does not support 2 EC devices, so
these people need to implement second in AML.
So, it might be worth noting that Linux can handle any number of EC devices.


Regards,
Alex.