ACPI: EC: Add wait for irq storm

Merge of poll and irq modes accelerated EC transaction, so
that keyboard starts to suffer again. Add msleep(1) into
transaction path for the storm to allow keyboard controller
to do its job.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=14747

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 0473309..d6471bb 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -259,7 +259,6 @@
 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
 	ret = ec_poll(ec);
-	pr_debug(PREFIX "transaction end\n");
 	spin_lock_irqsave(&ec->curr_lock, tmp);
 	ec->curr = NULL;
 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
@@ -316,6 +315,7 @@
 	/* check if we received SCI during transaction */
 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
+		msleep(1);
 		/* it is safe to enable GPE outside of transaction */
 		acpi_enable_gpe(NULL, ec->gpe);
 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
@@ -323,6 +323,7 @@
 			"transactions will use polling mode\n");
 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 	}
+	pr_debug(PREFIX "transaction end\n");
 end:
 	if (ec->global_lock)
 		acpi_release_global_lock(glk);