diff options
| author | Qipan Li <Qipan.Li@csr.com> | 2014-07-03 21:26:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-09 17:37:00 -0700 |
| commit | 7282cec90365533befce1552ab09edbcd0af0dbd (patch) | |
| tree | 746863b71b6ed12fbaaedfe6f41541fad5c056b9 /drivers/tty | |
| parent | a9977620a448f12a7337daca452fd20e89a96e23 (diff) | |
serial: sirf: transfer more bytes once to decrease interrupts
the current codes send 1 bytes, then after getting TX done interrupt,
send subsequent bytes. it causes redundant interrupts.
for example, if we have 3 bytes in TX buffer, the TX flow is:
1. send 1 byte
2. get TX down interrupt
3. send the left 2 bytes
4. get TX down interrupt
this patch moves to send more bytes and decrease interrupts, the new
flow is:
1. send 3 bytes
2. get TX down interrupt
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/sirfsoc_uart.c | 3 | ||||
| -rw-r--r-- | drivers/tty/serial/sirfsoc_uart.h | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c index 9b4d71cff00d..4102192687ee 100644 --- a/drivers/tty/serial/sirfsoc_uart.c +++ b/drivers/tty/serial/sirfsoc_uart.c @@ -290,7 +290,8 @@ static void sirfsoc_uart_start_tx(struct uart_port *port) if (sirfport->tx_dma_chan) sirfsoc_uart_tx_with_dma(sirfport); else { - sirfsoc_uart_pio_tx_chars(sirfport, 1); + sirfsoc_uart_pio_tx_chars(sirfport, + SIRFSOC_UART_IO_TX_REASONABLE_CNT); wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START); if (!sirfport->is_marco) wr_regl(port, ureg->sirfsoc_int_en_reg, diff --git a/drivers/tty/serial/sirfsoc_uart.h b/drivers/tty/serial/sirfsoc_uart.h index 69a62ebd3afc..6a7ebf7ef130 100644 --- a/drivers/tty/serial/sirfsoc_uart.h +++ b/drivers/tty/serial/sirfsoc_uart.h @@ -449,4 +449,4 @@ struct sirfsoc_uart_port { /* I/O Mode */ #define SIRFSOC_UART_IO_RX_MAX_CNT 256 -#define SIRFSOC_UART_IO_TX_REASONABLE_CNT 6 +#define SIRFSOC_UART_IO_TX_REASONABLE_CNT 256 |