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Diffstat (limited to 'Documentation/ABI/testing/sysfs-firmware-acpi')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-acpi | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi new file mode 100644 index 00000000000..9470ed9afcc --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-acpi @@ -0,0 +1,99 @@ +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 . * + error:0 + ff_gbl_lock:0 + ff_pmtimer:0 + ff_pwr_btn:0 + ff_rt_clk:0 + ff_slp_btn:0 + gpe00:0 + gpe01:0 + gpe02:0 + gpe03:0 + gpe04:0 + gpe05:0 + gpe06:0 + gpe07:0 + gpe08:0 + gpe09:174 + gpe0A:0 + gpe0B:0 + gpe0C:0 + gpe0D:0 + gpe0E:0 + gpe0F:0 + gpe10:0 + gpe11:60 + gpe12:0 + gpe13:0 + gpe14:0 + gpe15:0 + gpe16:0 + gpe17:0 + gpe18:0 + gpe19:7 + gpe1A:0 + gpe1B:0 + gpe1C:0 + gpe1D:0 + gpe1E:0 + gpe1F:0 + gpe_all:241 + sci:241 + + 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. + + 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. |