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authorZhang Rui <rui.zhang@intel.com>2008-06-20 09:42:47 +0800
committerAndi Kleen <andi@basil.nowhere.org>2008-07-16 23:27:04 +0200
commit71b58cbb0c30d1f78636a48c4721529449d6ea37 (patch)
treeb2271201121c7ecd4d275b19772dcc1e64575712 /Documentation
parent9c9f6d052dc6f469431461a97d49cf9c5558b8ad (diff)
ACPI: Enhance /sys/firmware/interrupts to allow enable/disable/clear from user-space
Allow users to enable/disable/clear a specific & valid GPE/Fixed Event in user space. This is useful for debugging, especially for some interrupt storm issues. All wakeup GPEs are disabled and they can not be enabled at runtime, and we mark them as invalid. All GPEs that don't have a _Lxx/_Exx method are marked as invalid. All Fixed Events that don't have an event handler are marked as invalid and they can't be enabled until an event handler is registered. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Ling Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'Documentation')
-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 9470ed9afcc..f27be7d1a49 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
+