[SERIAL] Convert fifosize to an unsigned int

Some UARTs have more than 255 bytes of FIFO, which can't be
represented by an unsigned char.  Change the kernel's internal
structure to be an unsigned int, but still export an unsigned char
via the TIOCGSERIAL ioctl.  If the TIOCSSERIAL ioctl provides a
fifo size of 0, assume this means "don't change" otherwise we'll
corrupt the larger fifo sizes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index 6459edc7f5c5e09d23bef78c590abfe677a5a813..1b2cdc91c228deeb2918bdd053bd591b2b54ff20 100644 (file)
--- 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 17839e753e4cfb1fb550832d8613b0ec579c83ef..3805f467b2f51c92edf62c2963900626b88d42ff 100644 (file)
--- 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 bd14858121ea2065fdd399c58c48dd6e1f513812..966e2e8a1740606a2848af06c5db6ce0c3d12b84 100644 (file)
--- 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)