[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 6459edc..1b2cdc91c 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -728,8 +728,7 @@
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 17839e7..3805f46 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -691,7 +691,8 @@
(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 @@
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 bd14858..966e2e8 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -214,10 +214,11 @@
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)