[ACPI] GPE storm detected on FS Amilo Pro

From: Jacek Luczak
Date: Wed Jan 21 2009 - 09:46:23 EST

Hi All,

I've got that ,,GPE storm detected'' issue on my Fujitsu Siemens Amilo Pro
notebook. I was using (which was fine) for a long while and recently
started testing some latest git versions starting from 2.6.29-rc2 where I've
discovered that issue. So I've made some back kernels and it shows up from
2.6.26 kernel. Bisection between 2.6.25 and 2.6.26 shows that patch:

fa95ba04e6ba11d71e1b87becd054b38faf546c8 is first bad commit
commit fa95ba04e6ba11d71e1b87becd054b38faf546c8
Author: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Date: Fri Mar 21 19:36:02 2008 +0300

ACPI: EC: Detect irq storm

Problem seems to be that hw fails to clear GPE after we service it and write 1
into corresponding bit. Thus, as soon as we get interrupts enabled again, we
receive a new one. Google gives too many results for "acer interrupt storm" for
this being one-broken-machine case.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9998

Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>

The bug[1] (reopened recently) seems to be quite different than the one in my
case. I've got no ,,side effects'' of that GPE storm. Notebook works fine and I
didn't discovered any interrupts problems. Up to 2.6.28 GPE storm information is
printed early[2]:

Setting up standard PCI resources
ACPI: EC: Look up EC in DSDT
ACPI: Interpreter enabled
ACPI: (supports S0 S3 S4 S5)
ACPI: Using IOAPIC for interrupt routing
ACPI: EC: non-query interrupt received, switching to interrupt mode
ACPI: EC: GPE storm detected, disabling EC GPE
ACPI: EC: GPE = 0x17, I/O: command/status = 0x66, data = 0x62
ACPI: EC: driver started in poll mode
ACPI: PCI Root Bridge [PCI0] (0000:00)

While recent git[3] which I'm now running, shows it after setting-up AC adapter[4]:

ACPI: AC Adapter [ADP1] (on-line)
ACPI: EC: GPE storm detected, transactions will use polling mode
Switched to high resolution mode on CPU 1
Switched to high resolution mode on CPU 0
ACPI: EC: missing confirmations, switch off interrupt mode.
ACPI: Battery Slot [BAT0] (battery present)
input: Power Button (FF) as /class/input/input0
ACPI: Power Button (FF) [PWRF]
input: Lid Switch as /class/input/input1
ACPI: Lid Switch [LID0]
input: Sleep Button (CM) as /class/input/input2
ACPI: Sleep Button (CM) [SLPB]

I'm not sure if the origin of that GPE storm is the same in both cases. Will try
to do bisection here later if needed.

NOTE: In git kernel I've noticed that after boot and obtaining IP from DHCP I've
got such message:

Jan 21 14:44:32 difrost kernel: sky2 eth0: enabling interface
Jan 21 14:44:33 difrost kernel: sky2 eth0: Link is up at 100 Mbps, full duplex,
flow control rx
Jan 21 14:45:36 difrost kernel: ACPI: EC: missing confirmations, switch off
interrupt mode.

This is not fully reproducible, didn't shown on [4].


[1] http://bugzilla.kernel.org/show_bug.cgi?id=9998
[2] Full dmesg:
[3] Kernel version: 2.6.29-rc2-12097-gf3b8436-dirty (marked dirty, due to fix
for XFS bug found here)
[4] Full git kernel dmesg:
[5] /proc/interrupts from git kernel:
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