From: Ling Ming <ming.m.lin@xxxxxxxxx>
Dectect GPE storm and disable a certain GPE if needed.
Introduce a new module parameter "debug_gpe_storm" as a runtime switch to
enable/disable this mechanism. The default value is TRUE, user can
"echo 0 > /sys/modules/acpi/parameters/debug_gpe_storm" to disable it.
Note: we try to disable a GPE if it's fired more than 1000 times in a second.
And this 1000/s is just a wild guess currently. Need more tests to get a
proper value.
Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/acpi/events/evgpe.c | 15 +++++++++++-
drivers/acpi/system.c | 55 ++++++++++++++++++++++++++++++++++++++++----
include/acpi/acpiosxf.h | 2 -
3 files changed, 65 insertions(+), 7 deletions(-)
Index: linux-2.6/drivers/acpi/events/evgpe.c
===================================================================
--- linux-2.6.orig/drivers/acpi/events/evgpe.c 2008-06-20 09:27:00.000000000 +0800
+++ linux-2.6/drivers/acpi/events/evgpe.c 2008-06-20 09:34:32.000000000 +0800
@@ -623,7 +623,20 @@
ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
- acpi_os_gpe_count(gpe_number);
+ if (acpi_os_gpe_storm_detect(gpe_number)) {
+ /*
+ * GPE storm detected, disable it automatically
+ * To disable gpe storm detection:
+ * "echo 0 > /sys/module/acpi/parameters/debug_gpe_storm"
+ */
+ acpi_status status = acpi_ev_disable_gpe(gpe_event_info);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status,
+ "Unable to disable GPE[%2X]", gpe_number));
+ }
+
+ return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
+ }
/*
* If edge-triggered, clear the GPE status bit now. Note that
Index: linux-2.6/drivers/acpi/system.c
===================================================================
--- linux-2.6.orig/drivers/acpi/system.c 2008-06-20 09:27:00.000000000 +0800
+++ linux-2.6/drivers/acpi/system.c 2008-06-20 09:34:32.000000000 +0800
@@ -168,9 +168,14 @@
#define NUM_COUNTERS_EXTRA 3
#define ACPI_EVENT_VALID 0x01
+#define GPE_STORM_INTERVAL HZ
+#define GPE_STORM_THRESHOLD 1000
+
struct event_counter {
u32 count;
u32 flags;
+ u32 storm;
+ unsigned long last_time;
};
static struct event_counter *all_counters;
@@ -263,20 +268,60 @@
return;
}
-void acpi_os_gpe_count(u32 gpe_number)
+/*
+ * acpi_gbl_gpe_lock is already acquired in acpi_ev_gpe_detect
+ */
+int check_gpe_storm(u32 gpe_number)
{
+ struct event_counter *gpe_counter;
+
+ if (gpe_number >= num_gpes)
+ return 0;
+
+ gpe_counter = &all_counters[gpe_number];
+
+ if (time_after(jiffies, gpe_counter->last_time + GPE_STORM_INTERVAL)) {
+ gpe_counter->storm = 0;
+ gpe_counter->last_time = jiffies;
+ }
+
+ gpe_counter->storm++;
+ if (gpe_counter->storm > GPE_STORM_THRESHOLD) {
+ printk(KERN_WARNING "GPE[%2X] storm detected,"
+ "%d interrupts in %d milliseconds.\n",
+ gpe_number, gpe_counter->storm, GPE_STORM_INTERVAL);
+ gpe_counter->storm = 0;
+ gpe_counter->last_time = jiffies;
+
+ return 1;
+ }
+
+ return 0;
+}
+
+static int debug_gpe_storm = 1;
+module_param(debug_gpe_storm, bool, 0644);
+
+int acpi_os_gpe_storm_detect(u32 gpe_number)
+{
+ int storm = 0;
+
acpi_gpe_count++;
if (!all_counters)
- return;
+ return storm;
- if (gpe_number < num_gpes)
+ if (gpe_number < num_gpes) {
all_counters[gpe_number].count++;
+
+ /* If debug_gpe_storm enabled, check gpe storm */
+ if (debug_gpe_storm)
+ storm = check_gpe_storm(gpe_number);
+ }
else
all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_ERROR].
count++;
-
- return;
+ return storm;
}
void acpi_os_fixed_event_count(u32 event_number)
Index: linux-2.6/include/acpi/acpiosxf.h
===================================================================
--- linux-2.6.orig/include/acpi/acpiosxf.h 2008-06-20 09:27:00.000000000 +0800
+++ linux-2.6/include/acpi/acpiosxf.h 2008-06-20 09:34:32.000000000 +0800
@@ -181,7 +181,7 @@
acpi_status
acpi_os_remove_interrupt_handler(u32 gsi, acpi_osd_handler service_routine);
-void acpi_os_gpe_count(u32 gpe_number);
+int acpi_os_gpe_storm_detect(u32 gpe_number);
void acpi_os_fixed_event_count(u32 fixed_event_number);
/*
--
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