atom feed10 messages in org.kernel.vger.linux-acpiRe: Problem: ACPI related soft lockup...
FromSent OnAttachments
Thomas LindrothOct 6, 2008 4:23 am 
Thomas LindrothOct 8, 2008 12:20 am 
Alexey StarikovskiyOct 8, 2008 12:42 am 
Alexey StarikovskiyOct 8, 2008 1:49 am.patch
Thomas LindrothOct 8, 2008 3:48 am 
Thomas RenningerOct 8, 2008 4:08 am 
Alexey StarikovskiyOct 8, 2008 4:52 am 
Thomas RenningerOct 8, 2008 3:19 pm 
Len BrownOct 8, 2008 6:50 pm 
Thomas LindrothOct 9, 2008 12:46 am 
Subject:Re: Problem: ACPI related soft lockup on Fujitsu-Siemens AMILO Si 2636
From:Alexey Starikovskiy (
Date:Oct 8, 2008 12:42:29 am

Thomas Lindroth wrote:

I've done some debugging of this problem myself and reached some conclusions.

I tried activating the ACPI_LV_INFO ACPI debug mode and observed what happens when the system is under load. I saved one trace and put it in the file acpi_debug_log at

When the temp goes over the ACPI passive trip point the processor gets throttled. It usually never goes over T4 before the temp falls below the passive temp but sometimes it reaches the highest T7. If it reach T7 the next call to _TMP or _L18 never returns. I've confirmed this by running echo T7 > /proc/acpi/processor/CPU*/throttling and then tried to read from /proc/acpi/thermal_zone/TZ00/temperature and it fails in the same way.

I've tried activating the ACPI_LV_PARSE ACPI debug mode, enter T7 and read from temp. I put the result of that in the trace_debug file at the same adress.

The AML call chain looks like this _TMP -> PMRD -> RCMD -> WIBF WIBF always returns 1 causing the interpreter to get stuck in the while loop in PMRD.

While (RCMD (0x80, Local0)) { Noop Noop Store (PMUC, Local5) If (And (Local5, One, Local2)) { Store (PMUD, Local5) } }

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.