pch_uart: Support modem status interrupt
Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index d035f8f..d11096c 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -1043,10 +1043,15 @@
int ret = 0;
unsigned char iid;
unsigned long flags;
+ int next = 1;
+ u8 msr;
spin_lock_irqsave(&priv->port.lock, flags);
handled = 0;
- while ((iid = pch_uart_hal_get_iid(priv)) > 1) {
+ while (next) {
+ iid = pch_uart_hal_get_iid(priv);
+ if (iid & PCH_UART_IIR_IP) /* No Interrupt */
+ break;
switch (iid) {
case PCH_UART_IID_RLS: /* Receiver Line Status */
lsr = pch_uart_hal_get_line_status(priv);
@@ -1080,12 +1085,18 @@
ret = handle_tx(priv);
break;
case PCH_UART_IID_MS: /* Modem Status */
- ret = PCH_UART_HANDLED_MS_INT;
+ msr = pch_uart_hal_get_modem(priv);
+ next = 0; /* MS ir prioirty is the lowest. So, MS ir
+ means final interrupt */
+ if ((msr & UART_MSR_ANY_DELTA) == 0)
+ break;
+ ret |= PCH_UART_HANDLED_MS_INT;
break;
default: /* Never junp to this label */
dev_err(priv->port.dev, "%s:iid=%02x (%lu)\n", __func__,
iid, jiffies);
ret = -1;
+ next = 0;
break;
}
handled |= (unsigned int)ret;