1 files changed, 48 insertions, 35 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 762b4cc9d7b1..f09386e9745f 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -78,6 +78,9 @@ enum {
         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
 };
 
+#define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
+#define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
+
 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 module_param(ec_delay, uint, 0644);
@@ -109,7 +112,7 @@ struct transaction {
         u8 ri;
         u8 wlen;
         u8 rlen;
-        bool done;
+        u8 flags;
 };
 
 struct acpi_ec *boot_ec, *first_ec;
@@ -150,63 +153,68 @@ static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
         outb(data, ec->data_addr);
 }
 
-static int ec_transaction_done(struct acpi_ec *ec)
+static int ec_transaction_completed(struct acpi_ec *ec)
 {
         unsigned long flags;
         int ret = 0;
         spin_lock_irqsave(&ec->lock, flags);
-        if (!ec->curr || ec->curr->done)
+        if (!ec->curr || (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
                 ret = 1;
         spin_unlock_irqrestore(&ec->lock, flags);
         return ret;
 }
 
-static void start_transaction(struct acpi_ec *ec)
-{
-        ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
-        ec->curr->done = false;
-        acpi_ec_write_cmd(ec, ec->curr->command);
-}
-
 static void advance_transaction(struct acpi_ec *ec)
 {
-        unsigned long flags;
         struct transaction *t;
         u8 status;
 
-        spin_lock_irqsave(&ec->lock, flags);
         pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
         status = acpi_ec_read_status(ec);
         t = ec->curr;
         if (!t)
-                goto unlock;
-        if (t->wlen > t->wi) {
-                if ((status & ACPI_EC_FLAG_IBF) == 0)
-                        acpi_ec_write_data(ec,
-                                t->wdata[t->wi++]);
-                else
-                        goto err;
-        } else if (t->rlen > t->ri) {
-                if ((status & ACPI_EC_FLAG_OBF) == 1) {
-                        t->rdata[t->ri++] = acpi_ec_read_data(ec);
-                        if (t->rlen == t->ri)
-                                t->done = true;
+                goto err;
+        if (t->flags & ACPI_EC_COMMAND_POLL) {
+                if (t->wlen > t->wi) {
+                        if ((status & ACPI_EC_FLAG_IBF) == 0)
+                                acpi_ec_write_data(ec, t->wdata[t->wi++]);
+                        else
+                                goto err;
+                } else if (t->rlen > t->ri) {
+                        if ((status & ACPI_EC_FLAG_OBF) == 1) {
+                                t->rdata[t->ri++] = acpi_ec_read_data(ec);
+                                if (t->rlen == t->ri)
+                                        t->flags |= ACPI_EC_COMMAND_COMPLETE;
+                        } else
+                                goto err;
+                } else if (t->wlen == t->wi &&
+                           (status & ACPI_EC_FLAG_IBF) == 0)
+                        t->flags |= ACPI_EC_COMMAND_COMPLETE;
+                return;
+        } else {
+                if ((status & ACPI_EC_FLAG_IBF) == 0) {
+                        acpi_ec_write_cmd(ec, t->command);
+                        t->flags |= ACPI_EC_COMMAND_POLL;
                 } else
                         goto err;
-        } else if (t->wlen == t->wi &&
-                   (status & ACPI_EC_FLAG_IBF) == 0)
-                t->done = true;
-        goto unlock;
+                return;
+        }
 err:
         /*
          * If SCI bit is set, then don't think it's a false IRQ
          * otherwise will take a not handled IRQ as a false one.
          */
-        if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
-                ++t->irq_count;
+        if (!(status & ACPI_EC_FLAG_SCI)) {
+                if (in_interrupt() && t)
+                        ++t->irq_count;
+        }
+}
 
-unlock:
-        spin_unlock_irqrestore(&ec->lock, flags);
+static void start_transaction(struct acpi_ec *ec)
+{
+        ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
+        ec->curr->flags = 0;
+        advance_transaction(ec);
 }
 
 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
@@ -231,15 +239,17 @@ static int ec_poll(struct acpi_ec *ec)
                         /* don't sleep with disabled interrupts */
                         if (EC_FLAGS_MSI || irqs_disabled()) {
                                 udelay(ACPI_EC_MSI_UDELAY);
-                                if (ec_transaction_done(ec))
+                                if (ec_transaction_completed(ec))
                                         return 0;
                         } else {
                                 if (wait_event_timeout(ec->wait,
-                                                ec_transaction_done(ec),
+                                                ec_transaction_completed(ec),
                                                 msecs_to_jiffies(1)))
                                         return 0;
                         }
+                        spin_lock_irqsave(&ec->lock, flags);
                         advance_transaction(ec);
+                        spin_unlock_irqrestore(&ec->lock, flags);
                 } while (time_before(jiffies, delay));
                 pr_debug("controller reset, restart transaction\n");
                 spin_lock_irqsave(&ec->lock, flags);
@@ -637,10 +647,13 @@ static int ec_check_sci(struct acpi_ec *ec, u8 state)
 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
         u32 gpe_number, void *data)
 {
+        unsigned long flags;
         struct acpi_ec *ec = data;
 
+        spin_lock_irqsave(&ec->lock, flags);
         advance_transaction(ec);
-        if (ec_transaction_done(ec) &&
+        spin_unlock_irqrestore(&ec->lock, flags);
+        if (ec_transaction_completed(ec) &&
             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
                 wake_up(&ec->wait);
                 ec_check_sci(ec, acpi_ec_read_status(ec));