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-rw-r--r--Documentation/ABI/testing/sysfs-firmware-acpi127
1 files changed, 87 insertions, 40 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi
index 9470ed9afcc0..f27be7d1a49f 100644
--- a/Documentation/ABI/testing/sysfs-firmware-acpi
+++ b/Documentation/ABI/testing/sysfs-firmware-acpi
@@ -29,46 +29,46 @@ Description:
$ 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
+ 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
sci - The total number of times the ACPI SCI
has claimed an interrupt.
@@ -89,6 +89,13 @@ Description:
error - an interrupt that can't be accounted for above.
+ invalid: it's either a wakeup GPE or a GPE/Fixed Event that
+ doesn't have an event handler.
+
+ disable: the GPE/Fixed Event is valid but disabled.
+
+ enable: the GPE/Fixed Event is valid and enabled.
+
Root has permission to clear any of these counters. Eg.
# echo 0 > gpe11
@@ -97,3 +104,43 @@ Description:
None of these counters has an effect on the function
of the system, they are simply statistics.
+
+ 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
+ 0
+ # press the power button for 3 times;
+ # cat ff_pwr_btn
+ 3
+ # echo disable > ff_pwr_btn
+ # cat ff_pwr_btn
+ disable
+ # press the power button for 3 times;
+ # cat ff_pwr_btn
+ disable
+ # echo enable > ff_pwr_btn
+ # cat ff_pwr_btn
+ 4
+ /*
+ * 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
+ 7
+ # 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
+ 7
+