1 files changed, 70 insertions, 76 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 7b4178393e34..06b78e5e33a1 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -65,16 +65,18 @@ enum ec_command {
 /* EC events */
 enum ec_event {
         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
-        ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
+        ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
 };
 
 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 
-static enum ec_mode {
-        EC_INTR = 1,            /* Output buffer full */
-        EC_POLL,                /* Input buffer empty */
-} acpi_ec_mode = EC_INTR;
+enum {
+        EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
+        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
+        EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
+        EC_FLAGS_ONLY_IBF_GPE,          /* Expect GPE only for IBF = 0 event */
+};
 
 static int acpi_ec_remove(struct acpi_device *device, int type);
 static int acpi_ec_start(struct acpi_device *device);
@@ -116,9 +118,8 @@ static struct acpi_ec {
         unsigned long command_addr;
         unsigned long data_addr;
         unsigned long global_lock;
+        unsigned long flags;
         struct mutex lock;
-        atomic_t query_pending;
-        atomic_t event_count;
         wait_queue_head_t wait;
         struct list_head list;
         u8 handlers_installed;
@@ -148,45 +149,54 @@ static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
         outb(data, ec->data_addr);
 }
 
-static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
-                                       unsigned old_count)
+static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 {
-        u8 status = acpi_ec_read_status(ec);
-        if (old_count == atomic_read(&ec->event_count))
+        if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
                 return 0;
         if (event == ACPI_EC_EVENT_OBF_1) {
-                if (status & ACPI_EC_FLAG_OBF)
+                if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
                         return 1;
         } else if (event == ACPI_EC_EVENT_IBF_0) {
-                if (!(status & ACPI_EC_FLAG_IBF))
+                if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
                         return 1;
         }
 
         return 0;
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
-                        unsigned count, int force_poll)
+static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
-        if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
+        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),
+                                       msecs_to_jiffies(ACPI_EC_DELAY)))
+                        return 0;
+                clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+                if (acpi_ec_check_status(ec, event)) {
+                        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 {
+                                /* 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 {
                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
+                clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                 while (time_before(jiffies, delay)) {
-                        if (acpi_ec_check_status(ec, event, 0))
+                        if (acpi_ec_check_status(ec, event))
                                 return 0;
                 }
-        } else {
-                if (wait_event_timeout(ec->wait,
-                                       acpi_ec_check_status(ec, event, count),
-                                       msecs_to_jiffies(ACPI_EC_DELAY)) ||
-                    acpi_ec_check_status(ec, event, 0)) {
-                        return 0;
-                } else {
-                        printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
+        }
+        printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
                                " status = %d, expect_event = %d\n",
                                acpi_ec_read_status(ec), event);
-                }
-        }
-
         return -ETIME;
 }
 
@@ -196,39 +206,42 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
                                         int force_poll)
 {
         int result = 0;
-        unsigned count = atomic_read(&ec->event_count);
+        set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
         acpi_ec_write_cmd(ec, command);
 
         for (; wdata_len > 0; --wdata_len) {
-                result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
+                result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
                 if (result) {
                         printk(KERN_ERR PREFIX
                                "write_cmd timeout, command = %d\n", command);
                         goto end;
                 }
-                count = atomic_read(&ec->event_count);
+                set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                 acpi_ec_write_data(ec, *(wdata++));
         }
 
         if (!rdata_len) {
-                result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
+                result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
                 if (result) {
                         printk(KERN_ERR PREFIX
                                "finish-write timeout, command = %d\n", command);
                         goto end;
                 }
-        } else if (command == ACPI_EC_COMMAND_QUERY) {
-                atomic_set(&ec->query_pending, 0);
-        }
+        } else if (command == ACPI_EC_COMMAND_QUERY)
+                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 
         for (; rdata_len > 0; --rdata_len) {
-                result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
+                if (test_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags))
+                        force_poll = 1;
+                result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
                 if (result) {
                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
                                command);
                         goto end;
                 }
-                count = atomic_read(&ec->event_count);
+                /* Don't expect GPE after last read */
+                if (rdata_len > 1)
+                        set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                 *(rdata++) = acpi_ec_read_data(ec);
         }
       end:
@@ -258,10 +271,7 @@ static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
                 }
         }
 
-        /* Make sure GPE is enabled before doing transaction */
-        acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-
-        status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
+        status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
         if (status) {
                 printk(KERN_ERR PREFIX
                        "input buffer is not empty, aborting transaction\n");
@@ -435,9 +445,9 @@ EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 
 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 {
-        struct acpi_ec_query_handler *handler;
+        struct acpi_ec_query_handler *handler, *tmp;
         mutex_lock(&ec->lock);
-        list_for_each_entry(handler, &ec->list, node) {
+        list_for_each_entry_safe(handler, tmp, &ec->list, node) {
                 if (query_bit == handler->query_bit) {
                         list_del(&handler->node);
                         kfree(handler);
@@ -476,23 +486,24 @@ static void acpi_ec_gpe_query(void *ec_cxt)
 static u32 acpi_ec_gpe_handler(void *data)
 {
         acpi_status status = AE_OK;
-        u8 value;
         struct acpi_ec *ec = data;
 
-        atomic_inc(&ec->event_count);
-
-        if (acpi_ec_mode == EC_INTR) {
+        clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+        if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
                 wake_up(&ec->wait);
-        }
 
-        value = acpi_ec_read_status(ec);
-        if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
-                atomic_set(&ec->query_pending, 1);
-                status =
-                    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
+        if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
+                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))) {
+                /* 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 status == AE_OK ?
+        return ACPI_SUCCESS(status) ?
             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 }
 
@@ -641,13 +652,10 @@ static struct acpi_ec *make_acpi_ec(void)
         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
         if (!ec)
                 return NULL;
-
-        atomic_set(&ec->query_pending, 1);
-        atomic_set(&ec->event_count, 1);
+        ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
         mutex_init(&ec->lock);
         init_waitqueue_head(&ec->wait);
         INIT_LIST_HEAD(&ec->list);
-
         return ec;
 }
 
@@ -741,6 +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;
 }
 
@@ -833,7 +843,7 @@ static int acpi_ec_start(struct acpi_device *device)
         ret = ec_install_handlers(ec);
 
         /* EC is fully operational, allow queries */
-        atomic_set(&ec->query_pending, 0);
+        clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
         return ret;
 }
 
@@ -924,20 +934,4 @@ static void __exit acpi_ec_exit(void)
 
         return;
 }
-#endif                          /* 0 */
-
-static int __init acpi_ec_set_intr_mode(char *str)
-{
-        int intr;
-
-        if (!get_option(&str, &intr))
-                return 0;
-
-        acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
-
-        printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
-
-        return 1;
-}
-
-__setup("ec_intr=", acpi_ec_set_intr_mode);
+#endif  /* 0 */