From fa95ba04e6ba11d71e1b87becd054b38faf546c8 Mon Sep 17 00:00:00 2001 From: Alexey Starikovskiy Date: Fri, 21 Mar 2008 19:36:02 +0300 Subject: 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: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/ec.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index da67d22..f0e8216 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -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; } -- cgit v1.1