[ACPI] Enable EC Burst Mode
authorDmitry Torokhov <dtor@mail.ru>
Sat, 19 Mar 2005 06:10:05 +0000 (01:10 -0500)
committerLen Brown <len.brown@intel.com>
Tue, 12 Jul 2005 03:52:48 +0000 (23:52 -0400)
Fixes several Embedded Controller issues, including
button failure and battery status AE_TIME failure.

http://bugzilla.kernel.org/show_bug.cgi?id=3851

Based on patch by: Andi Kleen <ak@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/acpi/ec.c

index fdf143b405be7fb638685a7bf0bb104239348dd4..69b04d430f00262e98f625bf0229a1b69f9c8c32 100644 (file)
@@ -31,6 +31,7 @@
 #include <linux/delay.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/interrupt.h>
 #include <asm/io.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
@@ -49,17 +50,19 @@ ACPI_MODULE_NAME            ("acpi_ec")
 
 #define ACPI_EC_FLAG_OBF       0x01    /* Output buffer full */
 #define ACPI_EC_FLAG_IBF       0x02    /* Input buffer full */
+#define ACPI_EC_FLAG_BURST     0x10    /* burst mode */
 #define ACPI_EC_FLAG_SCI       0x20    /* EC-SCI occurred */
 
 #define ACPI_EC_EVENT_OBF      0x01    /* Output buffer full */
 #define ACPI_EC_EVENT_IBE      0x02    /* Input buffer empty */
 
-#define ACPI_EC_UDELAY         100     /* Poll @ 100us increments */
-#define ACPI_EC_UDELAY_COUNT   1000    /* Wait 10ms max. during EC ops */
+#define ACPI_EC_DELAY          50      /* Wait 50ms max. during EC ops */
 #define ACPI_EC_UDELAY_GLK     1000    /* Wait 1ms max. to get global lock */
 
 #define ACPI_EC_COMMAND_READ   0x80
 #define ACPI_EC_COMMAND_WRITE  0x81
+#define ACPI_EC_BURST_ENABLE   0x82
+#define ACPI_EC_BURST_DISABLE  0x83
 #define ACPI_EC_COMMAND_QUERY  0x84
 
 static int acpi_ec_add (struct acpi_device *device);
@@ -87,7 +90,11 @@ struct acpi_ec {
        struct acpi_generic_address     command_addr;
        struct acpi_generic_address     data_addr;
        unsigned long                   global_lock;
-       spinlock_t                      lock;
+       unsigned int                    expect_event;
+       atomic_t                        leaving_burst; /* 0 : No, 1 : Yes, 2: abort*/
+       atomic_t                        pending_gpe;
+       struct semaphore                sem;
+       wait_queue_head_t               wait;
 };
 
 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
@@ -100,59 +107,138 @@ static struct acpi_device *first_ec;
                              Transaction Management
    -------------------------------------------------------------------------- */
 
-static int
-acpi_ec_wait (
-       struct acpi_ec          *ec,
-       u8                      event)
+static inline u32 acpi_ec_read_status(struct acpi_ec *ec)
 {
-       u32                     acpi_ec_status = 0;
-       u32                     i = ACPI_EC_UDELAY_COUNT;
+       u32     status = 0;
 
-       if (!ec)
-               return -EINVAL;
+       acpi_hw_low_level_read(8, &status, &ec->status_addr);
+       return status;
+}
+
+static int acpi_ec_wait(struct acpi_ec *ec, unsigned int event)
+{
+       int     result = 0;
+
+       ACPI_FUNCTION_TRACE("acpi_ec_wait");
 
-       /* Poll the EC status register waiting for the event to occur. */
+       ec->expect_event = event;
+       smp_mb();
+
+       result = wait_event_interruptible_timeout(ec->wait,
+                                       !ec->expect_event,
+                                       msecs_to_jiffies(ACPI_EC_DELAY));
+       
+       ec->expect_event = 0;
+       smp_mb();
+
+       if (result < 0){
+               ACPI_DEBUG_PRINT((ACPI_DB_ERROR," result  = %d ", result));
+               return_VALUE(result);
+       }
+
+       /*
+        * Verify that the event in question has actually happened by
+        * querying EC status. Do the check even if operation timed-out
+        * to make sure that we did not miss interrupt.
+        */
        switch (event) {
        case ACPI_EC_EVENT_OBF:
-               do {
-                       acpi_hw_low_level_read(8, &acpi_ec_status, &ec->status_addr);
-                       if (acpi_ec_status & ACPI_EC_FLAG_OBF)
-                               return 0;
-                       udelay(ACPI_EC_UDELAY);
-               } while (--i>0);
+               if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
+                       return_VALUE(0);
                break;
+
        case ACPI_EC_EVENT_IBE:
-               do {
-                       acpi_hw_low_level_read(8, &acpi_ec_status, &ec->status_addr);
-                       if (!(acpi_ec_status & ACPI_EC_FLAG_IBF))
-                               return 0;
-                       udelay(ACPI_EC_UDELAY);
-               } while (--i>0);
+               if (~acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
+                       return_VALUE(0);
                break;
-       default:
-               return -EINVAL;
        }
 
-       return -ETIME;
+       return_VALUE(-ETIME);
 }
 
 
+
+static int
+acpi_ec_enter_burst_mode (
+       struct acpi_ec          *ec)
+{
+       u32                     tmp = 0;
+       int                     status = 0;
+
+       ACPI_FUNCTION_TRACE("acpi_ec_enter_burst_mode");
+
+       status = acpi_ec_read_status(ec);
+       if (status != -EINVAL &&
+               !(status & ACPI_EC_FLAG_BURST)){
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"entering burst mode \n"));
+               acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->command_addr);
+               status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+               if (status){
+                       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR," status = %d\n", status));
+                       return_VALUE(-EINVAL);
+               }
+               acpi_hw_low_level_read(8, &tmp, &ec->data_addr);
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+               if(tmp != 0x90 ) {/* Burst ACK byte*/
+                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"Ack failed \n"));
+                       return_VALUE(-EINVAL);
+               }
+       } else
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"already be in burst mode \n"));
+       atomic_set(&ec->leaving_burst , 0);
+       return_VALUE(0);
+}
+
+static int
+acpi_ec_leave_burst_mode (
+       struct acpi_ec          *ec)
+{
+       int                     status =0;
+
+       ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");
+
+       atomic_set(&ec->leaving_burst , 1);
+       status = acpi_ec_read_status(ec);
+       if (status != -EINVAL &&
+               (status & ACPI_EC_FLAG_BURST)){
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"leaving burst mode\n"));
+               acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->command_addr);
+               status = acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);
+               if (status){
+                       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"------->wait fail\n"));
+                       return_VALUE(-EINVAL);
+               }
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+               status = acpi_ec_read_status(ec);
+               if (status != -EINVAL &&
+                       (status & ACPI_EC_FLAG_BURST)) {
+                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"------->status fail\n"));
+                       return_VALUE(-EINVAL);
+               }
+       }else
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"already be in Non-burst mode \n"));
+       ACPI_DEBUG_PRINT((ACPI_DB_INFO,"leaving burst mode\n"));
+
+       return_VALUE(0);
+}
+
 static int
 acpi_ec_read (
        struct acpi_ec          *ec,
        u8                      address,
        u32                     *data)
 {
-       acpi_status             status = AE_OK;
-       int                     result = 0;
-       unsigned long           flags = 0;
-       u32                     glk = 0;
+       int                     status = 0;
+       u32                     glk;
 
        ACPI_FUNCTION_TRACE("acpi_ec_read");
 
        if (!ec || !data)
                return_VALUE(-EINVAL);
 
+retry:
        *data = 0;
 
        if (ec->global_lock) {
@@ -160,32 +246,50 @@ acpi_ec_read (
                if (ACPI_FAILURE(status))
                        return_VALUE(-ENODEV);
        }
-       
-       spin_lock_irqsave(&ec->lock, flags);
+
+       WARN_ON(in_interrupt());
+       down(&ec->sem);
+
+       if(acpi_ec_enter_burst_mode(ec))
+               goto end;
 
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->command_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       if (result)
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+       if (status) {
                goto end;
+       }
 
        acpi_hw_low_level_write(8, address, &ec->data_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-       if (result)
+       status= acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+       if (status){
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
                goto end;
-
+       }
 
        acpi_hw_low_level_read(8, data, &ec->data_addr);
+       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
                *data, address));
-
+       
 end:
-       spin_unlock_irqrestore(&ec->lock, flags);
+       acpi_ec_leave_burst_mode(ec);
+       up(&ec->sem);
 
        if (ec->global_lock)
                acpi_release_global_lock(glk);
 
-       return_VALUE(result);
+       if(atomic_read(&ec->leaving_burst) == 2){
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
+               while(!atomic_read(&ec->pending_gpe)){
+                       msleep(1);      
+               }
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+               goto retry;
+       }
+
+       return_VALUE(status);
 }
 
 
@@ -195,49 +299,80 @@ acpi_ec_write (
        u8                      address,
        u8                      data)
 {
-       int                     result = 0;
-       acpi_status             status = AE_OK;
-       unsigned long           flags = 0;
-       u32                     glk = 0;
+       int                     status = 0;
+       u32                     glk;
+       u32                     tmp;
 
        ACPI_FUNCTION_TRACE("acpi_ec_write");
 
        if (!ec)
                return_VALUE(-EINVAL);
-
+retry:
        if (ec->global_lock) {
                status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
                if (ACPI_FAILURE(status))
                        return_VALUE(-ENODEV);
        }
 
-       spin_lock_irqsave(&ec->lock, flags);
+       WARN_ON(in_interrupt());
+       down(&ec->sem);
+
+       if(acpi_ec_enter_burst_mode(ec))
+               goto end;
+
+       status = acpi_ec_read_status(ec);
+       if (status != -EINVAL &&
+               !(status & ACPI_EC_FLAG_BURST)){
+               acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->command_addr);
+               status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+               if (status)
+                       goto end;
+               acpi_hw_low_level_read(8, &tmp, &ec->data_addr);
+               if(tmp != 0x90 ) /* Burst ACK byte*/
+                       goto end;
+       }
+       /*Now we are in burst mode*/
 
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->command_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       if (result)
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+       if (status){
                goto end;
+       }
 
        acpi_hw_low_level_write(8, address, &ec->data_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       if (result)
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       if (status){
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
                goto end;
+       }
 
        acpi_hw_low_level_write(8, data, &ec->data_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       if (result)
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+       if (status)
                goto end;
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
                data, address));
 
 end:
-       spin_unlock_irqrestore(&ec->lock, flags);
+       acpi_ec_leave_burst_mode(ec);
+       up(&ec->sem);
 
        if (ec->global_lock)
                acpi_release_global_lock(glk);
 
-       return_VALUE(result);
+       if(atomic_read(&ec->leaving_burst) == 2){
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
+               while(!atomic_read(&ec->pending_gpe)){
+                       msleep(1);      
+               }
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+               goto retry;
+       }
+
+       return_VALUE(status);
 }
 
 /*
@@ -289,16 +424,14 @@ acpi_ec_query (
        struct acpi_ec          *ec,
        u32                     *data)
 {
-       int                     result = 0;
-       acpi_status             status = AE_OK;
-       unsigned long           flags = 0;
-       u32                     glk = 0;
+       int                     status = 0;
+       u32                     glk;
 
        ACPI_FUNCTION_TRACE("acpi_ec_query");
 
        if (!ec || !data)
                return_VALUE(-EINVAL);
-
+retry:
        *data = 0;
 
        if (ec->global_lock) {
@@ -307,29 +440,43 @@ acpi_ec_query (
                        return_VALUE(-ENODEV);
        }
 
+       down(&ec->sem);
+       if(acpi_ec_enter_burst_mode(ec))
+               goto end;
        /*
         * Query the EC to find out which _Qxx method we need to evaluate.
         * Note that successful completion of the query causes the ACPI_EC_SCI
         * bit to be cleared (and thus clearing the interrupt source).
         */
-       spin_lock_irqsave(&ec->lock, flags);
-
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->command_addr);
-       result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-       if (result)
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+       if (status){
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
                goto end;
-       
+       }
+
        acpi_hw_low_level_read(8, data, &ec->data_addr);
+       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
        if (!*data)
-               result = -ENODATA;
+               status = -ENODATA;
 
 end:
-       spin_unlock_irqrestore(&ec->lock, flags);
+       acpi_ec_leave_burst_mode(ec);
+       up(&ec->sem);
 
        if (ec->global_lock)
                acpi_release_global_lock(glk);
 
-       return_VALUE(result);
+       if(atomic_read(&ec->leaving_burst) == 2){
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
+               while(!atomic_read(&ec->pending_gpe)){
+                       msleep(1);      
+               }
+               acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+               goto retry;
+       }
+
+       return_VALUE(status);
 }
 
 
@@ -347,42 +494,29 @@ acpi_ec_gpe_query (
        void                    *ec_cxt)
 {
        struct acpi_ec          *ec = (struct acpi_ec *) ec_cxt;
-       u32                     value = 0;
-       unsigned long           flags = 0;
+       u32                     value;
+       int                     result = -ENODATA;
        static char             object_name[5] = {'_','Q','0','0','\0'};
        const char              hex[] = {'0','1','2','3','4','5','6','7',
                                         '8','9','A','B','C','D','E','F'};
 
        ACPI_FUNCTION_TRACE("acpi_ec_gpe_query");
 
-       if (!ec_cxt)
-               goto end;       
+       if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI)
+               result = acpi_ec_query(ec, &value);
 
-       spin_lock_irqsave(&ec->lock, flags);
-       acpi_hw_low_level_read(8, &value, &ec->command_addr);
-       spin_unlock_irqrestore(&ec->lock, flags);
-
-       /* TBD: Implement asynch events!
-        * NOTE: All we care about are EC-SCI's.  Other EC events are
-        * handled via polling (yuck!).  This is because some systems
-        * treat EC-SCIs as level (versus EDGE!) triggered, preventing
-        *  a purely interrupt-driven approach (grumble, grumble).
-        */
-       if (!(value & ACPI_EC_FLAG_SCI))
+       if (result)
                goto end;
 
-       if (acpi_ec_query(ec, &value))
-               goto end;
-       
        object_name[2] = hex[((value >> 4) & 0x0F)];
        object_name[3] = hex[(value & 0x0F)];
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s\n", object_name));
 
        acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
-
-end:
-       acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+       atomic_dec(&ec->pending_gpe);
+end:   
+       return;
 }
 
 static u32
@@ -390,6 +524,7 @@ acpi_ec_gpe_handler (
        void                    *data)
 {
        acpi_status             status = AE_OK;
+       u32                     value;
        struct acpi_ec          *ec = (struct acpi_ec *) data;
 
        if (!ec)
@@ -397,13 +532,39 @@ acpi_ec_gpe_handler (
 
        acpi_disable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
 
-       status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
-               acpi_ec_gpe_query, ec);
+       value = acpi_ec_read_status(ec);
 
-       if (status == AE_OK)
-               return ACPI_INTERRUPT_HANDLED;
-       else
-               return ACPI_INTERRUPT_NOT_HANDLED;
+       if((value & ACPI_EC_FLAG_IBF) &&
+               !(value & ACPI_EC_FLAG_BURST) &&
+                       (atomic_read(&ec->leaving_burst) == 0)) { 
+       /*
+        * the embedded controller disables 
+        * burst mode for any reason other 
+        * than the burst disable command
+        * to process critical event.
+        */
+               atomic_set(&ec->leaving_burst , 2); /* block current pending transaction
+                                       and retry */
+               wake_up(&ec->wait);
+       }else {
+               if ((ec->expect_event == ACPI_EC_EVENT_OBF &&
+                               (value & ACPI_EC_FLAG_OBF)) ||
+                               (ec->expect_event == ACPI_EC_EVENT_IBE &&
+                               !(value & ACPI_EC_FLAG_IBF))) {
+                       ec->expect_event = 0;
+                       wake_up(&ec->wait);
+                       
+               }
+       }
+
+       if (value & ACPI_EC_FLAG_SCI){
+               atomic_add(1, &ec->pending_gpe) ;
+               status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
+                                               acpi_ec_gpe_query, ec);
+       } 
+
+       return status == AE_OK ?
+               ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 }
 
 /* --------------------------------------------------------------------------
@@ -421,10 +582,8 @@ acpi_ec_space_setup (
         * The EC object is in the handler context and is needed
         * when calling the acpi_ec_space_handler.
         */
-       if(function == ACPI_REGION_DEACTIVATE) 
-               *return_context = NULL;
-       else 
-               *return_context = handler_context;
+       *return_context  = (function != ACPI_REGION_DEACTIVATE) ?
+                                               handler_context : NULL;
 
        return AE_OK;
 }
@@ -555,7 +714,7 @@ static int
 acpi_ec_add_fs (
        struct acpi_device      *device)
 {
-       struct proc_dir_entry   *entry = NULL;
+       struct proc_dir_entry   *entry;
 
        ACPI_FUNCTION_TRACE("acpi_ec_add_fs");
 
@@ -606,9 +765,9 @@ static int
 acpi_ec_add (
        struct acpi_device      *device)
 {
-       int                     result = 0;
-       acpi_status             status = AE_OK;
-       struct acpi_ec          *ec = NULL;
+       int                     result;
+       acpi_status             status;
+       struct acpi_ec          *ec;
        unsigned long           uid;
 
        ACPI_FUNCTION_TRACE("acpi_ec_add");
@@ -623,7 +782,10 @@ acpi_ec_add (
 
        ec->handle = device->handle;
        ec->uid = -1;
-       spin_lock_init(&ec->lock);
+       atomic_set(&ec->pending_gpe, 0);
+       atomic_set(&ec->leaving_burst , 1);
+       init_MUTEX(&ec->sem);
+       init_waitqueue_head(&ec->wait);
        strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
        strcpy(acpi_device_class(device), ACPI_EC_CLASS);
        acpi_driver_data(device) = ec;
@@ -637,7 +799,7 @@ acpi_ec_add (
        if (ec_ecdt && ec_ecdt->uid == uid) {
                acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
                        ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
-       
+
                acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit, &acpi_ec_gpe_handler);
 
                kfree(ec_ecdt);
@@ -677,7 +839,7 @@ acpi_ec_remove (
        struct acpi_device      *device,
        int                     type)
 {
-       struct acpi_ec          *ec = NULL;
+       struct acpi_ec          *ec;
 
        ACPI_FUNCTION_TRACE("acpi_ec_remove");
 
@@ -732,8 +894,8 @@ static int
 acpi_ec_start (
        struct acpi_device      *device)
 {
-       acpi_status             status = AE_OK;
-       struct acpi_ec          *ec = NULL;
+       acpi_status             status;
+       struct acpi_ec          *ec;
 
        ACPI_FUNCTION_TRACE("acpi_ec_start");
 
@@ -789,8 +951,8 @@ acpi_ec_stop (
        struct acpi_device      *device,
        int                     type)
 {
-       acpi_status             status = AE_OK;
-       struct acpi_ec          *ec = NULL;
+       acpi_status             status;
+       struct acpi_ec          *ec;
 
        ACPI_FUNCTION_TRACE("acpi_ec_stop");
 
@@ -832,7 +994,6 @@ acpi_fake_ecdt_callback (
        status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->gpe_bit);
        if (ACPI_FAILURE(status))
                return status;
-       spin_lock_init(&ec_ecdt->lock);
        ec_ecdt->global_lock = TRUE;
        ec_ecdt->handle = handle;
 
@@ -890,7 +1051,7 @@ acpi_ec_get_real_ecdt(void)
        acpi_status             status;
        struct acpi_table_ecdt  *ecdt_ptr;
 
-       status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING, 
+       status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
                (struct acpi_table_header **) &ecdt_ptr);
        if (ACPI_FAILURE(status))
                return -ENODEV;
@@ -905,11 +1066,12 @@ acpi_ec_get_real_ecdt(void)
                return -ENOMEM;
        memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 
+       init_MUTEX(&ec_ecdt->sem);
+       init_waitqueue_head(&ec_ecdt->wait);
        ec_ecdt->command_addr = ecdt_ptr->ec_control;
        ec_ecdt->status_addr = ecdt_ptr->ec_control;
        ec_ecdt->data_addr = ecdt_ptr->ec_data;
        ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
-       spin_lock_init(&ec_ecdt->lock);
        /* use the GL just to be safe */
        ec_ecdt->global_lock = TRUE;
        ec_ecdt->uid = ecdt_ptr->uid;
@@ -978,7 +1140,7 @@ error:
 
 static int __init acpi_ec_init (void)
 {
-       int                     result = 0;
+       int                     result;
 
        ACPI_FUNCTION_TRACE("acpi_ec_init");