ACPI: EC: Handle IRQ storm on Acer laptops
authorAlexey Starikovskiy <astarikovskiy@suse.de>
Tue, 11 Mar 2008 17:30:00 +0000 (13:30 -0400)
committerLen Brown <len.brown@intel.com>
Tue, 11 Mar 2008 17:30:00 +0000 (13:30 -0400)
On some Acer systems, the HW fails to clear the GPE source,
causing an interrupt storm.

So in EC interrupt mode, we count how many interrupts we
receive when waiting.  If we get more than 5, we give
up on interrupt mode and revert to polling mode.

Also, for polling mode to work on Acers, we need
to insert a delay.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/acpi/ec.c

index caf873c14bfb244a89ba9c322ada05c3c2b3c04e..2c77359dbdc968a242044562ea8e411527bb4ec5 100644 (file)
@@ -129,6 +129,7 @@ static struct acpi_ec {
        struct mutex lock;
        wait_queue_head_t wait;
        struct list_head list;
        struct mutex lock;
        wait_queue_head_t wait;
        struct list_head list;
+       atomic_t irq_count;
        u8 handlers_installed;
 } *boot_ec, *first_ec;
 
        u8 handlers_installed;
 } *boot_ec, *first_ec;
 
@@ -181,6 +182,8 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
        int ret = 0;
 
 {
        int ret = 0;
 
+       atomic_set(&ec->irq_count, 0);
+
        if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
                     test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
                force_poll = 1;
        if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
                     test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
                force_poll = 1;
@@ -227,6 +230,7 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
                while (time_before(jiffies, delay)) {
                        if (acpi_ec_check_status(ec, event))
                                goto end;
                while (time_before(jiffies, delay)) {
                        if (acpi_ec_check_status(ec, event))
                                goto end;
+                       msleep(5);
                }
        }
        pr_err(PREFIX "acpi_ec_wait timeout,"
                }
        }
        pr_err(PREFIX "acpi_ec_wait timeout,"
@@ -529,6 +533,13 @@ static u32 acpi_ec_gpe_handler(void *data)
        struct acpi_ec *ec = data;
 
        pr_debug(PREFIX "~~~> interrupt\n");
        struct acpi_ec *ec = data;
 
        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");
+               acpi_disable_gpe(NULL, ec->gpe, ACPI_ISR);
+               clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+               return ACPI_INTERRUPT_HANDLED;
+       }
        clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
        if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
                wake_up(&ec->wait);
        clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
        if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
                wake_up(&ec->wait);