[ACPI] Fix "ec_burst=1" mode latency issue

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

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 1ac5731..31067a0 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -234,18 +234,29 @@ static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event)
        ec->burst.expect_event = event;
        smp_mb();
 
-       result = wait_event_interruptible_timeout(ec->burst.wait,
+       switch (event) {
+       case ACPI_EC_EVENT_OBF:
+               if (acpi_ec_read_status(ec) & event) {
+                       ec->burst.expect_event = 0;
+                       return_VALUE(0);
+               }
+               break;
+
+       case ACPI_EC_EVENT_IBE:
+               if (~acpi_ec_read_status(ec) & event) {
+                       ec->burst.expect_event = 0;
+                       return_VALUE(0);
+               }
+               break;
+       }
+
+       result = wait_event_timeout(ec->burst.wait,
                                        !ec->burst.expect_event,
                                        msecs_to_jiffies(ACPI_EC_DELAY));
        
        ec->burst.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
@@ -280,14 +291,14 @@ acpi_ec_enter_burst_mode (
        status = acpi_ec_read_status(ec);
        if (status != -EINVAL &&
                !(status & ACPI_EC_FLAG_BURST)){
+               status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+               if(status)
+                       goto end;
                acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->common.command_addr);
                status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-               if (status){
-                       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
+               if (status)
                        return_VALUE(-EINVAL);
-               }
                acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
                if(tmp != 0x90 ) {/* Burst ACK byte*/
                        return_VALUE(-EINVAL);
                }
@@ -295,31 +306,19 @@ acpi_ec_enter_burst_mode (
 
        atomic_set(&ec->burst.leaving_burst , 0);
        return_VALUE(0);
+end:
+       printk("Error in acpi_ec_wait\n");
+       return_VALUE(-1);
 }
 
 static int
 acpi_ec_leave_burst_mode (
        union acpi_ec           *ec)
 {
-       int                     status =0;
 
        ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");
 
-       atomic_set(&ec->burst.leaving_burst , 1);
-       status = acpi_ec_read_status(ec);
-       if (status != -EINVAL &&
-               (status & ACPI_EC_FLAG_BURST)){
-               acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->common.command_addr);
-               status = acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);
-               if (status){
-                       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"------->wait fail\n"));
-                       return_VALUE(-EINVAL);
-               }
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-               status = acpi_ec_read_status(ec);
-       }
-
+       atomic_set(&ec->burst.leaving_burst, 1);
        return_VALUE(0);
 }
 
@@ -461,7 +460,6 @@ acpi_ec_burst_read (
        if (!ec || !data)
                return_VALUE(-EINVAL);
 
-retry:
        *data = 0;
 
        if (ec->common.global_lock) {
@@ -473,26 +471,25 @@ retry:
        WARN_ON(in_interrupt());
        down(&ec->burst.sem);
 
-       if(acpi_ec_enter_burst_mode(ec))
+       acpi_ec_enter_burst_mode(ec);
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       if (status) {
+               printk("read EC, IB not empty\n");
                goto end;
-
+       }
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->common.command_addr);
        status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
        if (status) {
-               goto end;
+               printk("read EC, IB not empty\n");
        }
 
        acpi_hw_low_level_write(8, address, &ec->common.data_addr);
        status= acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
        if (status){
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
+               printk("read EC, OB not full\n");
                goto end;
        }
-
        acpi_hw_low_level_read(8, data, &ec->common.data_addr);
-       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
                *data, address));
        
@@ -503,15 +500,6 @@ end:
        if (ec->common.global_lock)
                acpi_release_global_lock(glk);
 
-       if(atomic_read(&ec->burst.leaving_burst) == 2){
-               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-               while(atomic_read(&ec->burst.pending_gpe)){
-                       msleep(1);      
-               }
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-               goto retry;
-       }
-
        return_VALUE(status);
 }
 
@@ -524,13 +512,12 @@ acpi_ec_burst_write (
 {
        int                     status = 0;
        u32                     glk;
-       u32                     tmp;
 
        ACPI_FUNCTION_TRACE("acpi_ec_write");
 
        if (!ec)
                return_VALUE(-EINVAL);
-retry:
+
        if (ec->common.global_lock) {
                status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
                if (ACPI_FAILURE(status))
@@ -540,61 +527,35 @@ retry:
        WARN_ON(in_interrupt());
        down(&ec->burst.sem);
 
-       if(acpi_ec_enter_burst_mode(ec))
-               goto end;
+       acpi_ec_enter_burst_mode(ec);
 
-       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->common.command_addr);
-               status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-               if (status)
-                       goto end;
-               acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
-               if(tmp != 0x90 ) /* Burst ACK byte*/
-                       goto end;
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       if ( status) {
+               printk("write EC, IB not empty\n");
        }
-       /*Now we are in burst mode*/
-
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->common.command_addr);
        status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-       if (status){
-               goto end;
+       if (status) {
+               printk ("write EC, IB not empty\n");
        }
 
        acpi_hw_low_level_write(8, address, &ec->common.data_addr);
        status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
        if (status){
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-               goto end;
+               printk("write EC, IB not empty\n");
        }
 
        acpi_hw_low_level_write(8, data, &ec->common.data_addr);
-       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-       if (status)
-               goto end;
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
                data, address));
 
-end:
        acpi_ec_leave_burst_mode(ec);
        up(&ec->burst.sem);
 
        if (ec->common.global_lock)
                acpi_release_global_lock(glk);
 
-       if(atomic_read(&ec->burst.leaving_burst) == 2){
-               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-               while(atomic_read(&ec->burst.pending_gpe)){
-                       msleep(1);      
-               }
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-               goto retry;
-       }
-
        return_VALUE(status);
 }
 
@@ -719,8 +680,12 @@ acpi_ec_burst_query (
        }
 
        down(&ec->burst.sem);
-       if(acpi_ec_enter_burst_mode(ec))
+
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+       if (status) {
+               printk("query EC, IB not empty\n");
                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
@@ -729,27 +694,20 @@ acpi_ec_burst_query (
        acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->common.command_addr);
        status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
        if (status){
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
+               printk("query EC, OB not full\n");
                goto end;
        }
 
        acpi_hw_low_level_read(8, data, &ec->common.data_addr);
-       acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
        if (!*data)
                status = -ENODATA;
 
 end:
-       acpi_ec_leave_burst_mode(ec);
        up(&ec->burst.sem);
 
        if (ec->common.global_lock)
                acpi_release_global_lock(glk);
 
-       if(atomic_read(&ec->burst.leaving_burst) == 2){
-               ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-               acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
-               status = -ENODATA;
-       }
        return_VALUE(status);
 }
 
@@ -885,31 +843,21 @@ acpi_ec_gpe_burst_handler (
        if (!ec)
                return ACPI_INTERRUPT_NOT_HANDLED;
 
-       acpi_disable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
-
+       acpi_clear_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
        value = acpi_ec_read_status(ec);
 
-       if((value & ACPI_EC_FLAG_IBF) &&
-               !(value & ACPI_EC_FLAG_BURST) &&
-                       (atomic_read(&ec->burst.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->burst.leaving_burst , 2); /* block current pending transaction
-                                       and retry */
+       switch ( ec->burst.expect_event) {
+       case ACPI_EC_EVENT_OBF:
+               if (!(value & ACPI_EC_FLAG_OBF))
+                       break;
+       case ACPI_EC_EVENT_IBE:
+               if ((value & ACPI_EC_FLAG_IBF))
+                       break;
+               ec->burst.expect_event = 0;
                wake_up(&ec->burst.wait);
-       }else {
-               if ((ec->burst.expect_event == ACPI_EC_EVENT_OBF &&
-                               (value & ACPI_EC_FLAG_OBF)) ||
-                               (ec->burst.expect_event == ACPI_EC_EVENT_IBE &&
-                               !(value & ACPI_EC_FLAG_IBF))) {
-                       ec->burst.expect_event = 0;
-                       wake_up(&ec->burst.wait);
-                       return ACPI_INTERRUPT_HANDLED;
-               }
+               return ACPI_INTERRUPT_HANDLED;
+       default:
+               break;
        }
 
        if (value & ACPI_EC_FLAG_SCI){
@@ -1242,6 +1190,7 @@ acpi_ec_burst_add (
        if (result)
                goto end;
 
+       printk("burst-mode-ec-10-Aug\n");
        printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",
                acpi_device_name(device), acpi_device_bid(device),
                (u32) ec->common.gpe_bit);