2008-02-06 06:26:55 +00:00
|
|
|
What: /sys/firmware/acpi/interrupts/
|
|
|
|
|
Date: February 2008
|
|
|
|
|
Contact: Len Brown <lenb@kernel.org>
|
|
|
|
|
Description:
|
|
|
|
|
All ACPI interrupts are handled via a single IRQ,
|
|
|
|
|
the System Control Interrupt (SCI), which appears
|
|
|
|
|
as "acpi" in /proc/interrupts.
|
|
|
|
|
|
|
|
|
|
However, one of the main functions of ACPI is to make
|
|
|
|
|
the platform understand random hardware without
|
|
|
|
|
special driver support. So while the SCI handles a few
|
|
|
|
|
well known (fixed feature) interrupts sources, such
|
|
|
|
|
as the power button, it can also handle a variable
|
|
|
|
|
number of a "General Purpose Events" (GPE).
|
|
|
|
|
|
|
|
|
|
A GPE vectors to a specified handler in AML, which
|
|
|
|
|
can do a anything the BIOS writer wants from
|
|
|
|
|
OS context. GPE 0x12, for example, would vector
|
|
|
|
|
to a level or edge handler called _L12 or _E12.
|
|
|
|
|
The handler may do its business and return.
|
|
|
|
|
Or the handler may send send a Notify event
|
|
|
|
|
to a Linux device driver registered on an ACPI device,
|
|
|
|
|
such as a battery, or a processor.
|
|
|
|
|
|
|
|
|
|
To figure out where all the SCI's are coming from,
|
|
|
|
|
/sys/firmware/acpi/interrupts contains a file listing
|
|
|
|
|
every possible source, and the count of how many
|
|
|
|
|
times it has triggered.
|
|
|
|
|
|
|
|
|
|
$ cd /sys/firmware/acpi/interrupts
|
|
|
|
|
$ grep . *
|
2008-06-20 01:42:47 +00:00
|
|
|
error: 0
|
|
|
|
|
ff_gbl_lock: 0 enable
|
|
|
|
|
ff_pmtimer: 0 invalid
|
|
|
|
|
ff_pwr_btn: 0 enable
|
|
|
|
|
ff_rt_clk: 2 disable
|
|
|
|
|
ff_slp_btn: 0 invalid
|
|
|
|
|
gpe00: 0 invalid
|
|
|
|
|
gpe01: 0 enable
|
|
|
|
|
gpe02: 108 enable
|
|
|
|
|
gpe03: 0 invalid
|
|
|
|
|
gpe04: 0 invalid
|
|
|
|
|
gpe05: 0 invalid
|
|
|
|
|
gpe06: 0 enable
|
|
|
|
|
gpe07: 0 enable
|
|
|
|
|
gpe08: 0 invalid
|
|
|
|
|
gpe09: 0 invalid
|
|
|
|
|
gpe0A: 0 invalid
|
|
|
|
|
gpe0B: 0 invalid
|
|
|
|
|
gpe0C: 0 invalid
|
|
|
|
|
gpe0D: 0 invalid
|
|
|
|
|
gpe0E: 0 invalid
|
|
|
|
|
gpe0F: 0 invalid
|
|
|
|
|
gpe10: 0 invalid
|
|
|
|
|
gpe11: 0 invalid
|
|
|
|
|
gpe12: 0 invalid
|
|
|
|
|
gpe13: 0 invalid
|
|
|
|
|
gpe14: 0 invalid
|
|
|
|
|
gpe15: 0 invalid
|
|
|
|
|
gpe16: 0 invalid
|
|
|
|
|
gpe17: 1084 enable
|
|
|
|
|
gpe18: 0 enable
|
|
|
|
|
gpe19: 0 invalid
|
|
|
|
|
gpe1A: 0 invalid
|
|
|
|
|
gpe1B: 0 invalid
|
|
|
|
|
gpe1C: 0 invalid
|
|
|
|
|
gpe1D: 0 invalid
|
|
|
|
|
gpe1E: 0 invalid
|
|
|
|
|
gpe1F: 0 invalid
|
|
|
|
|
gpe_all: 1192
|
|
|
|
|
sci: 1194
|
2008-02-06 06:26:55 +00:00
|
|
|
|
|
|
|
|
sci - The total number of times the ACPI SCI
|
|
|
|
|
has claimed an interrupt.
|
|
|
|
|
|
|
|
|
|
gpe_all - count of SCI caused by GPEs.
|
|
|
|
|
|
|
|
|
|
gpeXX - count for individual GPE source
|
|
|
|
|
|
|
|
|
|
ff_gbl_lock - Global Lock
|
|
|
|
|
|
|
|
|
|
ff_pmtimer - PM Timer
|
|
|
|
|
|
|
|
|
|
ff_pwr_btn - Power Button
|
|
|
|
|
|
|
|
|
|
ff_rt_clk - Real Time Clock
|
|
|
|
|
|
|
|
|
|
ff_slp_btn - Sleep Button
|
|
|
|
|
|
|
|
|
|
error - an interrupt that can't be accounted for above.
|
|
|
|
|
|
2008-10-27 21:01:02 +00:00
|
|
|
invalid: it's either a GPE or a Fixed Event that
|
2008-06-20 01:42:47 +00:00
|
|
|
doesn't have an event handler.
|
|
|
|
|
|
|
|
|
|
disable: the GPE/Fixed Event is valid but disabled.
|
|
|
|
|
|
|
|
|
|
enable: the GPE/Fixed Event is valid and enabled.
|
|
|
|
|
|
2008-02-06 06:26:55 +00:00
|
|
|
Root has permission to clear any of these counters. Eg.
|
|
|
|
|
# echo 0 > gpe11
|
|
|
|
|
|
|
|
|
|
All counters can be cleared by clearing the total "sci":
|
|
|
|
|
# echo 0 > sci
|
|
|
|
|
|
|
|
|
|
None of these counters has an effect on the function
|
|
|
|
|
of the system, they are simply statistics.
|
2008-06-20 01:42:47 +00:00
|
|
|
|
|
|
|
|
Besides this, user can also write specific strings to these files
|
|
|
|
|
to enable/disable/clear ACPI interrupts in user space, which can be
|
|
|
|
|
used to debug some ACPI interrupt storm issues.
|
|
|
|
|
|
|
|
|
|
Note that only writting to VALID GPE/Fixed Event is allowed,
|
|
|
|
|
i.e. user can only change the status of runtime GPE and
|
|
|
|
|
Fixed Event with event handler installed.
|
|
|
|
|
|
|
|
|
|
Let's take power button fixed event for example, please kill acpid
|
|
|
|
|
and other user space applications so that the machine won't shutdown
|
|
|
|
|
when pressing the power button.
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
0 enabled
|
2008-06-20 01:42:47 +00:00
|
|
|
# press the power button for 3 times;
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
3 enabled
|
2008-06-20 01:42:47 +00:00
|
|
|
# echo disable > ff_pwr_btn
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
3 disabled
|
2008-06-20 01:42:47 +00:00
|
|
|
# press the power button for 3 times;
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
3 disabled
|
2008-06-20 01:42:47 +00:00
|
|
|
# echo enable > ff_pwr_btn
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
4 enabled
|
2008-06-20 01:42:47 +00:00
|
|
|
/*
|
|
|
|
|
* this is because the status bit is set even if the enable bit is cleared,
|
|
|
|
|
* and it triggers an ACPI fixed event when the enable bit is set again
|
|
|
|
|
*/
|
|
|
|
|
# press the power button for 3 times;
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
7 enabled
|
2008-06-20 01:42:47 +00:00
|
|
|
# echo disable > ff_pwr_btn
|
|
|
|
|
# press the power button for 3 times;
|
|
|
|
|
# echo clear > ff_pwr_btn /* clear the status bit */
|
|
|
|
|
# echo disable > ff_pwr_btn
|
|
|
|
|
# cat ff_pwr_btn
|
2008-10-27 21:01:02 +00:00
|
|
|
7 enabled
|
2008-06-20 01:42:47 +00:00
|
|
|
|
