USB: cypress_m8: only wake up MSR queue on changes
Only wake up MSR wait queue on actual modem-status changes.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 558605d..07e0033 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -1187,7 +1187,10 @@
if (priv->current_status != priv->prev_status) {
priv->diff_status |= priv->current_status ^
priv->prev_status;
- wake_up_interruptible(&port->port.delta_msr_wait);
+
+ if (priv->diff_status & UART_MSR_MASK)
+ wake_up_interruptible(&port->port.delta_msr_wait);
+
priv->prev_status = priv->current_status;
}
spin_unlock_irqrestore(&priv->lock, flags);