ACPI / EC: Don't count a SCI interrupt as a false one

Currently when advance_transaction() is called in EC interrupt handler,
if there is nothing driver can do with the interrupt, it will be taken
as a false one.

But this is not always true, as there may be a SCI EC interrupt fired
during normal read/write operation, which should not be counted as a
false one. This patch fixes the problem.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 8f8b644bba8d..354007d490d1 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -198,9 +198,13 @@ static void advance_transaction(struct acpi_ec *ec, u8 status)
                 t->done = true;
         goto unlock;
 err:
-        /* false interrupt, state didn't change */
-        if (in_interrupt())
+        /*
+         * 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;
+
 unlock:
         spin_unlock_irqrestore(&ec->lock, flags);
 }