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| author | Ben Dooks <ben.dooks@codethink.co.uk> | 2015-11-18 17:41:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-14 06:59:48 +0300 |
| commit | 88679739012cda64b1a45ee9dea16d04380dba71 (patch) | |
| tree | ed2430c80a710895825ae71e52f1382b456a6b0c /drivers/tty/serial/meson_uart.c | |
| parent | 00661dd855b5b174aa176a9ab9437d86ef4f8f1a (diff) | |
| download | linux-88679739012cda64b1a45ee9dea16d04380dba71.tar.xz | |
ARM: meson: serial: tx_empty fails to check for transmitter busy
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@codethink.co.uk>
Reported-by: Edward Cragg <edward.cragg@codethink.co.uk>
Tested-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/meson_uart.c')
| -rw-r--r-- | drivers/tty/serial/meson_uart.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index b87eb97e5e7a..54d1b9591b8d 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) |