The tx_empty() uart_op should only return empty if both the transmit fifo and the transmit state-machine are both idle. Add a test for the hardware's XMIT_BUSY flag. Note, this is possibly related to an issue where the port is being shutdown with paritally transmitted characters in it. Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> Reported-by: Edward Cragg <edward.cragg@xxxxxxxxxxxxxxx> --- drivers/tty/serial/meson_uart.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index b87eb97..54d1b95 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -57,6 +57,7 @@ #define AML_UART_RX_EMPTY BIT(20) #define AML_UART_TX_FULL BIT(21) #define AML_UART_TX_EMPTY BIT(22) +#define AML_UART_XMIT_BUSY BIT(25) #define AML_UART_ERR (AML_UART_PARITY_ERR | \ AML_UART_FRAME_ERR | \ AML_UART_TX_FIFO_WERR) @@ -100,7 +101,8 @@ static unsigned int meson_uart_tx_empty(struct uart_port *port) u32 val; val = readl(port->membase + AML_UART_STATUS); - return (val & AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0; + val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY); + return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0; } static void meson_uart_stop_tx(struct uart_port *port) -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
