diff options
Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 5a4e9d579585..763eb20fe321 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1249,20 +1249,19 @@ __acquires(&uap->port.lock) /* * Transmit a character - * There must be at least one free entry in the TX FIFO to accept the char. * - * Returns true if the FIFO might have space in it afterwards; - * returns false if the FIFO definitely became full. + * Returns true if the character was successfully queued to the FIFO. + * Returns false otherwise. */ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c) { + if (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) + return false; /* unable to transmit character */ + writew(c, uap->port.membase + UART01x_DR); uap->port.icount.tx++; - if (likely(uap->tx_irq_seen > 1)) - return true; - - return !(readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF); + return true; } static bool pl011_tx_chars(struct uart_amba_port *uap) @@ -1296,7 +1295,8 @@ static bool pl011_tx_chars(struct uart_amba_port *uap) return false; if (uap->port.x_char) { - pl011_tx_char(uap, uap->port.x_char); + if (!pl011_tx_char(uap, uap->port.x_char)) + goto done; uap->port.x_char = 0; --count; } @@ -1639,6 +1639,9 @@ static int pl011_startup(struct uart_port *port) writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS); + /* Assume that TX IRQ doesn't work until we see one: */ + uap->tx_irq_seen = 0; + spin_lock_irq(&uap->port.lock); /* restore RTS and DTR */ @@ -1702,7 +1705,7 @@ static void pl011_shutdown(struct uart_port *port) spin_lock_irq(&uap->port.lock); uap->im = 0; writew(uap->im, uap->port.membase + UART011_IMSC); - writew(0xffff & ~UART011_TXIS, uap->port.membase + UART011_ICR); + writew(0xffff, uap->port.membase + UART011_ICR); spin_unlock_irq(&uap->port.lock); pl011_dma_shutdown(uap); |