3 files changed, 7 insertions, 5 deletions

diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index 6459edc7f5c5..1b2cdc91c228 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -728,8 +728,7 @@ mpc52xx_uart_probe(struct platform_device *dev)
 
         spin_lock_init(&port->lock);
         port->uartclk   = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
-        port->fifosize  = 255; /* Should be 512 ! But it can't be */
-                               /* stored in a unsigned char       */
+        port->fifosize  = 512;
         port->iotype    = UPIO_MEM;
         port->flags     = UPF_BOOT_AUTOCONF |
                           ( uart_console(port) ? 0 : UPF_IOREMAP );
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 17839e753e4c..3805f467b2f5 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -691,7 +691,8 @@ static int uart_set_info(struct uart_state *state,
                     (new_serial.baud_base != port->uartclk / 16) ||
                     (close_delay != state->close_delay) ||
                     (closing_wait != state->closing_wait) ||
-                    (new_serial.xmit_fifo_size != port->fifosize) ||
+                    (new_serial.xmit_fifo_size &&
+                     new_serial.xmit_fifo_size != port->fifosize) ||
                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
                         goto exit;
                 port->flags = ((port->flags & ~UPF_USR_MASK) |
@@ -796,7 +797,8 @@ static int uart_set_info(struct uart_state *state,
         port->custom_divisor   = new_serial.custom_divisor;
         state->close_delay     = close_delay;
         state->closing_wait    = closing_wait;
-        port->fifosize         = new_serial.xmit_fifo_size;
+        if (new_serial.xmit_fifo_size)
+                port->fifosize = new_serial.xmit_fifo_size;
         if (state->info->tty)
                 state->info->tty->low_latency =
                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index bd14858121ea..966e2e8a1740 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -214,10 +214,11 @@ struct uart_port {
         unsigned char __iomem   *membase;               /* read/write[bwl] */
         unsigned int            irq;                    /* irq number */
         unsigned int            uartclk;                /* base uart clock */
-        unsigned char           fifosize;               /* tx fifo size */
+        unsigned int            fifosize;               /* tx fifo size */
         unsigned char           x_char;                 /* xon/xoff char */
         unsigned char           regshift;               /* reg offset shift */
         unsigned char           iotype;                 /* io access style */
+        unsigned char           unused1;
 
 #define UPIO_PORT               (0)
 #define UPIO_HUB6               (1)