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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 12:45:58 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 12:45:58 -0500
commitf0f1b3364ae7f48084bdf2837fb979ff59622523 (patch)
treee5ef68c0071f44178cc8d1948b64e216d57422aa /Documentation/ABI
parent4383f18b7f94a4d668c5eec68645c75d44556235 (diff)
parentb7143156c9ceee1a072c57aac8729d2dec5b3bf1 (diff)
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (112 commits) ACPI: fix build warning Revert "cpuidle: build fix for non-x86" ACPI: update intrd DSDT override console messages ACPI: update DSDT override documentation ACPI: Add "acpi_no_initrd_override" kernel parameter ACPI: its a directory not a folder.... ACPI: misc cleanups ACPI: add missing prink prefix strings ACPI: cleanup acpi.h ACPICA: fix CONFIG_ACPI_DEBUG_FUNC_TRACE build ACPI: video: Ignore ACPI video devices that aren't present in hardware ACPI: video: reset brightness on resume ACPI: video: call ACPI notifier chain for ACPI video notifications ACPI: create notifier chain to get hotkey events to graphics driver ACPI: video: delete unused display switch on hotkey event code ACPI: video: create "brightness_switch_enabled" modparam cpuidle: Add a poll_idle method ACPI: cpuidle: Support C1 idle time accounting ACPI: enable MWAIT for C1 idle ACPI: idle: Fix acpi_safe_halt usages and interrupt enabling/disabling ...
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1What: /sys/firmware/acpi/interrupts/
2Date: February 2008
3Contact: Len Brown <lenb@kernel.org>
4Description:
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.