[ACPI] Disable EC burst mode w/o disabling EC interrupts

Need to de-couple the concept of polling/interrupts
vs burst/non-burst.

http://bugzilla.kernel.org/show_bug.cgi?id=4980

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

1 files changed, 20 insertions, 16 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 7e1a445955bc..6edfbe6f187c 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -213,19 +213,14 @@ static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event)
         smp_mb();
 
         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;
+        default:
+                break;
         }
 
         result = wait_event_timeout(ec->burst.wait,
@@ -255,7 +250,11 @@ static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event)
         return_VALUE(-ETIME);
 }
 
-static int acpi_ec_enter_burst_mode(union acpi_ec *ec)
+/*
+ * Note: samsung nv5000 doesn't work with ec burst mode.
+ * http://bugzilla.kernel.org/show_bug.cgi?id=4980
+ */
+int acpi_ec_enter_burst_mode(union acpi_ec *ec)
 {
         u32 tmp = 0;
         int status = 0;
@@ -270,8 +269,6 @@ static int acpi_ec_enter_burst_mode(union acpi_ec *ec)
                 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)
-                        return_VALUE(-EINVAL);
                 acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
                 if (tmp != 0x90) {      /* Burst ACK byte */
                         return_VALUE(-EINVAL);
@@ -285,13 +282,25 @@ static int acpi_ec_enter_burst_mode(union acpi_ec *ec)
         return_VALUE(-1);
 }
 
-static int acpi_ec_leave_burst_mode(union acpi_ec *ec)
+int acpi_ec_leave_burst_mode(union acpi_ec *ec)
 {
+        int status = 0;
 
         ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");
 
+        status = acpi_ec_read_status(ec);
+        if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)){
+                status = acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);
+                if(status)
+                        goto end;
+                acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->common.command_addr);
+                acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);
+        } 
         atomic_set(&ec->burst.leaving_burst, 1);
         return_VALUE(0);
+end:
+        printk("leave burst_mode:error \n");
+        return_VALUE(-1);
 }
 
 static int acpi_ec_read(union acpi_ec *ec, u8 address, u32 * data)
@@ -424,7 +433,6 @@ static int acpi_ec_burst_read(union acpi_ec *ec, u8 address, u32 * data)
         WARN_ON(in_interrupt());
         down(&ec->burst.sem);
 
-        acpi_ec_enter_burst_mode(ec);
         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
         if (status) {
                 printk("read EC, IB not empty\n");
@@ -448,7 +456,6 @@ static int acpi_ec_burst_read(union acpi_ec *ec, u8 address, u32 * data)
                           *data, address));
 
       end:
-        acpi_ec_leave_burst_mode(ec);
         up(&ec->burst.sem);
 
         if (ec->common.global_lock)
@@ -476,8 +483,6 @@ static int acpi_ec_burst_write(union acpi_ec *ec, u8 address, u8 data)
         WARN_ON(in_interrupt());
         down(&ec->burst.sem);
 
-        acpi_ec_enter_burst_mode(ec);
-
         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
         if (status) {
                 printk("write EC, IB not empty\n");
@@ -500,7 +505,6 @@ static int acpi_ec_burst_write(union acpi_ec *ec, u8 address, u8 data)
         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
                           data, address));
 
-        acpi_ec_leave_burst_mode(ec);
         up(&ec->burst.sem);
 
         if (ec->common.global_lock)