From: Narendra Hadke <nhadke@xxxxxxxxxxx>
For mvebu uart2, error bits are not cleared on buffer read.
This causes interrupt loop and system hang.
Signed-off-by: Narendra Hadke <nhadke@xxxxxxxxxxx>
Reviewed-by: Yi Guo <yi.guo@xxxxxxxxxx>
Reviewed-by: Nadav Haklai <nadavh@xxxxxxxxxxx>
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/tty/serial/mvebu-uart.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index 0429c2a54290..ff61a8d00014 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -265,6 +265,7 @@ static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
struct tty_port *tport = &port->state->port;
unsigned char ch = 0;
char flag = 0;
+ int ret;
do {
if (status & STAT_RX_RDY(port)) {
@@ -277,6 +278,16 @@ static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
port->icount.parity++;
}
+ /*
+ * For UART2, error bits are not cleared on buffer read.
+ * This causes interrupt loop and system hang.
+ */
+ if (IS_EXTENDED(port) && (status & STAT_BRK_ERR)) {
+ ret = readl(port->membase + UART_STAT);
+ ret |= STAT_BRK_ERR;
+ writel(ret, port->membase + UART_STAT);
+ }
+
if (status & STAT_BRK_DET) {
port->icount.brk++;
status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
--
2.20.1
