[PATCH 19/25] serial: timbuart: make sure last byte is sent when port is closed
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From: Greg Kroah-Hartman on 21 May 2010 13:00 From: Richard Röjfors <richard.rojfors(a)pelagicore.com> Fix a problem in early versions of the FPGA IP. In certain situations the IP reports that the FIFO is empty, but a byte is still clocked out. If a flush is done at that point the currently clocked byte is canceled. This causes incompatibilities with the upper layers when a port is closed, it waits until the FIFO is empty and then closes the port. During close the FIFO is flushed -> the last byte is not sent properly. Now the FIFO is only flushed if it is reported to be non-empty. Which makes the currently clocked out byte to finish. [akpm(a)linux-foundation.org: fix build] Signed-off-by: Richard Röjfors <richard.rojfors(a)pelagicore.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- drivers/serial/timbuart.c | 23 +++++++++++++---------- 1 files changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/serial/timbuart.c b/drivers/serial/timbuart.c index 62f389f..67ca642 100644 --- a/drivers/serial/timbuart.c +++ b/drivers/serial/timbuart.c @@ -68,12 +68,22 @@ static void timbuart_start_tx(struct uart_port *port) tasklet_schedule(&uart->tasklet); } +static unsigned int timbuart_tx_empty(struct uart_port *port) +{ + u32 isr = ioread32(port->membase + TIMBUART_ISR); + + return (isr & TXBE) ? TIOCSER_TEMT : 0; +} + static void timbuart_flush_buffer(struct uart_port *port) { - u8 ctl = ioread8(port->membase + TIMBUART_CTRL) | TIMBUART_CTRL_FLSHTX; + if (!timbuart_tx_empty(port)) { + u8 ctl = ioread8(port->membase + TIMBUART_CTRL) | + TIMBUART_CTRL_FLSHTX; - iowrite8(ctl, port->membase + TIMBUART_CTRL); - iowrite32(TXBF, port->membase + TIMBUART_ISR); + iowrite8(ctl, port->membase + TIMBUART_CTRL); + iowrite32(TXBF, port->membase + TIMBUART_ISR); + } } static void timbuart_rx_chars(struct uart_port *port) @@ -195,13 +205,6 @@ void timbuart_tasklet(unsigned long arg) dev_dbg(uart->port.dev, "%s leaving\n", __func__); } -static unsigned int timbuart_tx_empty(struct uart_port *port) -{ - u32 isr = ioread32(port->membase + TIMBUART_ISR); - - return (isr & TXBE) ? TIOCSER_TEMT : 0; -} - static unsigned int timbuart_get_mctrl(struct uart_port *port) { u8 cts = ioread8(port->membase + TIMBUART_CTRL); -- 1.7.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |