Commit fa95ba04 authored by Alexey Starikovskiy's avatar Alexey Starikovskiy Committed by Len Brown
Browse files

ACPI: EC: Detect irq storm 

Problem seems to be that hw fails to clear GPE after we service it and write 1
into corresponding bit. Thus, as soon as we get interrupts enabled again, we
receive a new one. Google gives too many results for "acer interrupt storm" for
this being one-broken-machine case.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9998



Signed-off-by: default avatarAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 223883b7

drivers/acpi/ec.c

+11 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ static struct acpi_ec { 
	wait_queue_head_t wait;

	struct list_head list;

	struct delayed_work work;

	atomic_t irq_count;

	u8 handlers_installed;

} *boot_ec, *first_ec;
@@ -171,6 +172,7 @@ static void ec_switch_to_poll_mode(struct acpi_ec *ec) 


static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)

{

	atomic_set(&ec->irq_count, 0);

	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&

	    likely(!force_poll)) {

		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
@@ -489,6 +491,12 @@ static u32 acpi_ec_gpe_handler(void *data) 
	u8 state = acpi_ec_read_status(ec);



	pr_debug(PREFIX "~~~> interrupt\n");

	atomic_inc(&ec->irq_count);

	if (atomic_read(&ec->irq_count) > 5) {

		pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");

		ec_switch_to_poll_mode(ec);

		goto end;

	}

	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);

	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))

		wake_up(&ec->wait);
@@ -507,6 +515,7 @@ static u32 acpi_ec_gpe_handler(void *data) 
		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);

		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);

	}

end:

	ec_schedule_ec_poll(ec);

	return ACPI_SUCCESS(status) ?

	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
@@ -515,6 +524,7 @@ static u32 acpi_ec_gpe_handler(void *data) 
static void do_ec_poll(struct work_struct *work)

{

	struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);

	atomic_set(&ec->irq_count, 0);

	(void)acpi_ec_gpe_handler(ec);

}
@@ -679,6 +689,7 @@ static struct acpi_ec *make_acpi_ec(void) 
	init_waitqueue_head(&ec->wait);

	INIT_LIST_HEAD(&ec->list);

	INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);

	atomic_set(&ec->irq_count, 0);

	return ec;

}

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