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
+