100 lines
2.2 KiB
Plaintext
100 lines
2.2 KiB
Plaintext
What: /sys/firmware/acpi/interrupts/
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Date: February 2008
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Contact: Len Brown <lenb@kernel.org>
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Description:
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All ACPI interrupts are handled via a single IRQ,
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the System Control Interrupt (SCI), which appears
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as "acpi" in /proc/interrupts.
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However, one of the main functions of ACPI is to make
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the platform understand random hardware without
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special driver support. So while the SCI handles a few
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well known (fixed feature) interrupts sources, such
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as the power button, it can also handle a variable
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number of a "General Purpose Events" (GPE).
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A GPE vectors to a specified handler in AML, which
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can do a anything the BIOS writer wants from
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OS context. GPE 0x12, for example, would vector
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to a level or edge handler called _L12 or _E12.
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The handler may do its business and return.
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Or the handler may send send a Notify event
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to a Linux device driver registered on an ACPI device,
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such as a battery, or a processor.
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To figure out where all the SCI's are coming from,
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/sys/firmware/acpi/interrupts contains a file listing
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every possible source, and the count of how many
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times it has triggered.
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$ cd /sys/firmware/acpi/interrupts
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$ grep . *
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error:0
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ff_gbl_lock:0
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ff_pmtimer:0
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ff_pwr_btn:0
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ff_rt_clk:0
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ff_slp_btn:0
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gpe00:0
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gpe01:0
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gpe02:0
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gpe03:0
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gpe04:0
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gpe05:0
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gpe06:0
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gpe07:0
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gpe08:0
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gpe09:174
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gpe0A:0
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gpe0B:0
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gpe0C:0
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gpe0D:0
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gpe0E:0
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gpe0F:0
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gpe10:0
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gpe11:60
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gpe12:0
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gpe13:0
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gpe14:0
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gpe15:0
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gpe16:0
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gpe17:0
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gpe18:0
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gpe19:7
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gpe1A:0
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gpe1B:0
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gpe1C:0
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gpe1D:0
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gpe1E:0
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gpe1F:0
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gpe_all:241
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sci:241
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sci - The total number of times the ACPI SCI
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has claimed an interrupt.
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gpe_all - count of SCI caused by GPEs.
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gpeXX - count for individual GPE source
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ff_gbl_lock - Global Lock
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ff_pmtimer - PM Timer
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ff_pwr_btn - Power Button
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ff_rt_clk - Real Time Clock
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ff_slp_btn - Sleep Button
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error - an interrupt that can't be accounted for above.
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Root has permission to clear any of these counters. Eg.
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# echo 0 > gpe11
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All counters can be cleared by clearing the total "sci":
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# echo 0 > sci
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None of these counters has an effect on the function
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of the system, they are simply statistics.
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