1 files changed, 14 insertions, 3 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 202db575d5db..bf60b24ebf54 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -173,12 +173,17 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
                         return 0;
                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                 if (acpi_ec_check_status(ec, event)) {
-                        if (event == ACPI_EC_EVENT_OBF_1)
+                        if (event == ACPI_EC_EVENT_OBF_1) {
                                 /* miss OBF = 1 GPE, don't expect it anymore */
+                                printk(KERN_INFO PREFIX "missing OBF_1 confirmation,"
+                                        "switching to degraded mode.\n");
                                 set_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags);
-                        else
+                        } else {
                                 /* missing GPEs, switch back to poll mode */
+                                printk(KERN_INFO PREFIX "missing IBF_1 confirmations,"
+                                        "switch off interrupt mode.\n");
                                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+                        }
                         return 0;
                 }
         } else {
@@ -491,8 +496,12 @@ static u32 acpi_ec_gpe_handler(void *data)
                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
                                 acpi_ec_gpe_query, ec);
-        } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags)))
+        } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
+                /* this is non-query, must be confirmation */
+                printk(KERN_INFO PREFIX "non-query interrupt received,"
+                        " switching to interrupt mode\n");
                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+        }
 
         return ACPI_SUCCESS(status) ?
             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
@@ -740,6 +749,8 @@ static int acpi_ec_add(struct acpi_device *device)
         acpi_ec_add_fs(device);
         printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
                           ec->gpe, ec->command_addr, ec->data_addr);
+        printk(KERN_INFO PREFIX "driver started in %s mode\n",
+                (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
         return 0;
 }