ACPI: EC: restart failed command

Restart current transaction if we recieved unexpected GPEs instead
of needed ones.

http://bugzilla.kernel.org/show_bug.cgi?id=11896

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index cebd65d..34c67ca 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -100,6 +100,8 @@ struct transaction {
        u8 *rdata;
        unsigned short irq_count;
        u8 command;
+       u8 wi;
+       u8 ri;
        u8 wlen;
        u8 rlen;
        bool done;
@@ -185,26 +187,34 @@ static int ec_transaction_done(struct acpi_ec *ec)
        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 gpe_transaction(struct acpi_ec *ec, u8 status)
 {
        unsigned long flags;
        spin_lock_irqsave(&ec->curr_lock, flags);
        if (!ec->curr)
                goto unlock;
-       if (ec->curr->wlen > 0) {
-               if ((status & ACPI_EC_FLAG_IBF) == 0) {
-                       acpi_ec_write_data(ec, *(ec->curr->wdata++));
-                       --ec->curr->wlen;
-               } else
+       if (ec->curr->wlen > ec->curr->wi) {
+               if ((status & ACPI_EC_FLAG_IBF) == 0)
+                       acpi_ec_write_data(ec,
+                               ec->curr->wdata[ec->curr->wi++]);
+               else
                        goto err;
-       } else if (ec->curr->rlen > 0) {
+       } else if (ec->curr->rlen > ec->curr->ri) {
                if ((status & ACPI_EC_FLAG_OBF) == 1) {
-                       *(ec->curr->rdata++) = acpi_ec_read_data(ec);
-                       if (--ec->curr->rlen == 0)
+                       ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
+                       if (ec->curr->rlen == ec->curr->ri)
                                ec->curr->done = true;
                } else
                        goto err;
-       } else if (ec->curr->wlen == 0 && (status & ACPI_EC_FLAG_IBF) == 0)
+       } else if (ec->curr->wlen == ec->curr->wi &&
+                  (status & ACPI_EC_FLAG_IBF) == 0)
                ec->curr->done = true;
        goto unlock;
 err:
@@ -219,6 +229,15 @@ static int acpi_ec_wait(struct acpi_ec *ec)
        if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
                               msecs_to_jiffies(ACPI_EC_DELAY)))
                return 0;
+       /* try restart command if we get any false interrupts */
+       if (ec->curr->irq_count &&
+           (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
+               pr_debug(PREFIX "controller reset, restart transaction\n");
+               start_transaction(ec);
+               if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
+                                       msecs_to_jiffies(ACPI_EC_DELAY)))
+                       return 0;
+       }
        /* missing GPEs, switch back to poll mode */
        if (printk_ratelimit())
                pr_info(PREFIX "missing confirmations, "
@@ -268,10 +287,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
        /* start transaction */
        spin_lock_irqsave(&ec->curr_lock, tmp);
        /* following two actions should be kept atomic */
-       t->irq_count = 0;
-       t->done = false;
        ec->curr = t;
-       acpi_ec_write_cmd(ec, ec->curr->command);
+       start_transaction(ec);
        if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
        spin_unlock_irqrestore(&ec->curr_lock, tmp);