From 3bc46b312b1486b1fe2db4246a34a30160d26d8d Mon Sep 17 00:00:00 2001
From: Maxime Bizon <mbizon@freebox.fr>
Date: Fri, 10 Jun 2011 23:17:58 +0200
Subject: [PATCH] serial: bcm63xx_uart: fix irq storm after rx fifo overrun.
RX fifo reset is required to clear irq.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/tty/serial/bcm63xx_uart.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
index a1a0e55d08077..c0b68b9cad911 100644
--- a/drivers/tty/serial/bcm63xx_uart.c
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -250,6 +250,20 @@ static void bcm_uart_do_rx(struct uart_port *port)
/* get overrun/fifo empty information from ier
* register */
iestat = bcm_uart_readl(port, UART_IR_REG);
+
+ if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
+ unsigned int val;
+
+ /* fifo reset is required to clear
+ * interrupt */
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val |= UART_CTL_RSTRXFIFO_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ port->icount.overrun++;
+ tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+ }
+
if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
break;
@@ -284,10 +298,6 @@ static void bcm_uart_do_rx(struct uart_port *port)
if (uart_handle_sysrq_char(port, c))
continue;
- if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
- port->icount.overrun++;
- tty_insert_flip_char(tty, 0, TTY_OVERRUN);
- }
if ((cstat & port->ignore_status_mask) == 0)
tty_insert_flip_char(tty, c, flag);
--
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