ACPI: EC: Handle IRQ storm on Acer laptops

[linux-2.6.git] / drivers / acpi / ec.c

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 987b967c74670728831af322571e4a182fb84d7e..2c77359dbdc968a242044562ea8e411527bb4ec5 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -129,6 +129,7 @@ static struct acpi_ec {
        struct mutex lock;
        wait_queue_head_t wait;
        struct list_head list;
+       atomic_t irq_count;
        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;
 
+       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;
@@ -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;
+                       msleep(5);
                }
        }
        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");
+       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);
@@ -573,7 +584,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
                      void *handler_context, void *region_context)
 {
        struct acpi_ec *ec = handler_context;
-       int result = 0, i = 0;
+       int result = 0, i;
        u8 temp = 0;
 
        if ((address > 0xFF) || !value || !handler_context)
@@ -585,7 +596,18 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
        if (bits != 8 && acpi_strict)
                return AE_BAD_PARAMETER;
 
-       while (bits - i > 0) {
+       acpi_ec_burst_enable(ec);
+
+       if (function == ACPI_READ) {
+               result = acpi_ec_read(ec, address, &temp);
+               *value = temp;
+       } else {
+               temp = 0xff & (*value);
+               result = acpi_ec_write(ec, address, temp);
+       }
+
+       for (i = 8; unlikely(bits - i > 0); i += 8) {
+               ++address;
                if (function == ACPI_READ) {
                        result = acpi_ec_read(ec, address, &temp);
                        (*value) |= ((acpi_integer)temp) << i;
@@ -593,10 +615,10 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
                        temp = 0xff & ((*value) >> i);
                        result = acpi_ec_write(ec, address, temp);
                }
-               i += 8;
-               ++address;
        }
 
+       acpi_ec_burst_disable(ec);
+
        switch (result) {
        case -EINVAL:
                return AE_BAD_PARAMETER;
@@ -932,7 +954,11 @@ int __init acpi_ec_ecdt_probe(void)
                boot_ec->command_addr = ecdt_ptr->control.address;
                boot_ec->data_addr = ecdt_ptr->data.address;
                boot_ec->gpe = ecdt_ptr->gpe;
-               boot_ec->handle = ACPI_ROOT_OBJECT;
+               if (ACPI_FAILURE(acpi_get_handle(NULL, ecdt_ptr->id,
+                               &boot_ec->handle))) {
+                       pr_info("Failed to locate handle for boot EC\n");
+                       boot_ec->handle = ACPI_ROOT_OBJECT;
+               }
        } else {
                /* This workaround is needed only on some broken machines,
                 * which require early EC, but fail to provide ECDT */