ARM: PL011: Separate hardware FIFO size from TTY FIFO size

With DMA support, we need to tell the TTY subsystem that the DMA buffer
is the size of the FIFO, otherwise things like tty_wait_until_sent()
will time out too early.  Keep (and use) the hardware value separately
from the port->fifosize.

This was part of a larger patch from Linus Walleij, with a little
modification.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index 6afdd9b..f9b6b82 100644 (file)
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -97,6 +97,7 @@ struct uart_amba_port {
        const struct vendor_data *vendor;
        unsigned int            im;             /* interrupt mask */
        unsigned int            old_status;
+       unsigned int            fifosize;       /* vendor-specific */
        unsigned int            lcrh_tx;        /* vendor-specific */
        unsigned int            lcrh_rx;        /* vendor-specific */
        bool                    autorts;
@@ -203,7 +204,7 @@ static void pl011_tx_chars(struct uart_amba_port *uap)
                return;
        }
 
-       count = uap->port.fifosize >> 1;
+       count = uap->fifosize >> 1;
        do {
                writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -541,7 +542,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
                if (!(termios->c_cflag & PARODD))
                        lcr_h |= UART01x_LCRH_EPS;
        }
-       if (port->fifosize > 1)
+       if (uap->fifosize > 1)
                lcr_h |= UART01x_LCRH_FEN;
 
        spin_lock_irqsave(&port->lock, flags);
@@ -871,12 +872,13 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
        uap->vendor = vendor;
        uap->lcrh_rx = vendor->lcrh_rx;
        uap->lcrh_tx = vendor->lcrh_tx;
+       uap->fifosize = vendor->fifosize;
        uap->port.dev = &dev->dev;
        uap->port.mapbase = dev->res.start;
        uap->port.membase = base;
        uap->port.iotype = UPIO_MEM;
        uap->port.irq = dev->irq[0];
-       uap->port.fifosize = vendor->fifosize;
+       uap->port.fifosize = uap->fifosize;
        uap->port.ops = &amba_pl011_pops;
        uap->port.flags = UPF_BOOT_AUTOCONF;
        uap->port.line = i;