summaryrefslogtreecommitdiff
path: root/drivers/tty
diff options
context:
space:
mode:
authorQipan Li <Qipan.Li@csr.com>2014-07-03 21:26:59 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-09 17:37:00 -0700
commit7282cec90365533befce1552ab09edbcd0af0dbd (patch)
tree746863b71b6ed12fbaaedfe6f41541fad5c056b9 /drivers/tty
parenta9977620a448f12a7337daca452fd20e89a96e23 (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.c3
-rw-r--r--drivers/tty/serial/sirfsoc_uart.h2
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