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Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 27f34a9f9cb7..a97f1ae11f78 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1293,7 +1293,18 @@ receive_chars(struct uart_8250_port *up, unsigned int *status)
char flag;
do {
- ch = serial_inp(up, UART_RX);
+ if (likely(lsr & UART_LSR_DR))
+ ch = serial_inp(up, UART_RX);
+ else
+ /*
+ * Intel 82571 has a Serial Over Lan device that will
+ * set UART_LSR_BI without setting UART_LSR_DR when
+ * it receives a break. To avoid reading from the
+ * receive buffer without UART_LSR_DR bit set, we
+ * just force the read character to be 0
+ */
+ ch = 0;
+
flag = TTY_NORMAL;
up->port.icount.rx++;
@@ -1342,7 +1353,7 @@ receive_chars(struct uart_8250_port *up, unsigned int *status)
ignore_char:
lsr = serial_inp(up, UART_LSR);
- } while ((lsr & UART_LSR_DR) && (max_count-- > 0));
+ } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
spin_unlock(&up->port.lock);
tty_flip_buffer_push(tty);
spin_lock(&up->port.lock);
@@ -1425,7 +1436,7 @@ serial8250_handle_port(struct uart_8250_port *up)
DEBUG_INTR("status = %x...", status);
- if (status & UART_LSR_DR)
+ if (status & (UART_LSR_DR | UART_LSR_BI))
receive_chars(up, &status);
check_modem_status(up);
if (status & UART_LSR_THRE)
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