Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.
1 What: /sys/firmware/acpi/interrupts/ 2 Date: February 2008 3 Contact: Len Brown <lenb[AT]kernel[DOT]org> 4 Description: 5 All ACPI interrupts are handled via a single IRQ, 6 the System Control Interrupt (SCI), which appears 7 as "acpi" in /proc/interrupts. 8 9 However, one of the main functions of ACPI is to make 10 the platform understand random hardware without 11 special driver support. So while the SCI handles a few 12 well known (fixed feature) interrupts sources, such 13 as the power button, it can also handle a variable 14 number of a "General Purpose Events" (GPE). 15 16 A GPE vectors to a specified handler in AML, which 17 can do a anything the BIOS writer wants from 18 OS context. GPE 0x12, for example, would vector 19 to a level or edge handler called _L12 or _E12. 20 The handler may do its business and return. 21 Or the handler may send send a Notify event 22 to a Linux device driver registered on an ACPI device, 23 such as a battery, or a processor. 24 25 To figure out where all the SCI's are coming from, 26 /sys/firmware/acpi/interrupts contains a file listing 27 every possible source, and the count of how many 28 times it has triggered. 29 30 $ cd /sys/firmware/acpi/interrupts 31 $ grep . * 32 error:0 33 ff_gbl_lock:0 34 ff_pmtimer:0 35 ff_pwr_btn:0 36 ff_rt_clk:0 37 ff_slp_btn:0 38 gpe00:0 39 gpe01:0 40 gpe02:0 41 gpe03:0 42 gpe04:0 43 gpe05:0 44 gpe06:0 45 gpe07:0 46 gpe08:0 47 gpe09:174 48 gpe0A:0 49 gpe0B:0 50 gpe0C:0 51 gpe0D:0 52 gpe0E:0 53 gpe0F:0 54 gpe10:0 55 gpe11:60 56 gpe12:0 57 gpe13:0 58 gpe14:0 59 gpe15:0 60 gpe16:0 61 gpe17:0 62 gpe18:0 63 gpe19:7 64 gpe1A:0 65 gpe1B:0 66 gpe1C:0 67 gpe1D:0 68 gpe1E:0 69 gpe1F:0 70 gpe_all:241 71 sci:241 72 73 sci - The total number of times the ACPI SCI 74 has claimed an interrupt. 75 76 gpe_all - count of SCI caused by GPEs. 77 78 gpeXX - count for individual GPE source 79 80 ff_gbl_lock - Global Lock 81 82 ff_pmtimer - PM Timer 83 84 ff_pwr_btn - Power Button 85 86 ff_rt_clk - Real Time Clock 87 88 ff_slp_btn - Sleep Button 89 90 error - an interrupt that can't be accounted for above. 91 92 Root has permission to clear any of these counters. Eg. 93 # echo 0 > gpe11 94 95 All counters can be cleared by clearing the total "sci": 96 # echo 0 > sci 97 98 None of these counters has an effect on the function 99 of the system, they are simply statistics.