Blackfin serial driver: fix overhead issue

Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 11 deletions

diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 408390f93db9..a8271d9c6202 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -240,24 +240,30 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
                 bfin_serial_stop_tx(&uart->port);
 }
 
-static irqreturn_t bfin_serial_int(int irq, void *dev_id)
+static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
+{
+        struct bfin_serial_port *uart = dev_id;
+
+        spin_lock(&uart->port.lock);
+        while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_RX_READY)
+                bfin_serial_rx_chars(uart);
+        spin_unlock(&uart->port.lock);
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
 {
         struct bfin_serial_port *uart = dev_id;
         unsigned short status;
 
         spin_lock(&uart->port.lock);
-        status = UART_GET_IIR(uart);
-        do {
-                if ((status & IIR_STATUS) == IIR_TX_READY)
-                        bfin_serial_tx_chars(uart);
-                if ((status & IIR_STATUS) == IIR_RX_READY)
-                        bfin_serial_rx_chars(uart);
-                status = UART_GET_IIR(uart);
-        } while (status & (IIR_TX_READY | IIR_RX_READY));
+        while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_TX_READY)
+                bfin_serial_tx_chars(uart);
         spin_unlock(&uart->port.lock);
         return IRQ_HANDLED;
 }
 
+
 static void bfin_serial_do_work(struct work_struct *work)
 {
         struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
@@ -545,14 +551,14 @@ static int bfin_serial_startup(struct uart_port *port)
         add_timer(&(uart->rx_dma_timer));
 #else
         if (request_irq
-            (uart->port.irq, bfin_serial_int, IRQF_DISABLED,
+            (uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
              "BFIN_UART_RX", uart)) {
                 printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
                 return -EBUSY;
         }
 
         if (request_irq
-            (uart->port.irq+1, bfin_serial_int, IRQF_DISABLED,
+            (uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
              "BFIN_UART_TX", uart)) {
                 printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
                 free_irq(uart->port.irq, uart);