Powerpc 8xx CPM_UART too many interrupts

Setting the fifo to only 1 byte generates one interrupt every 1ms at 9600 bauds.
This is too much. This patch reduces the threshold to speeds below 2400 bauds
like in the 8250 UART driver.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christophe Leroy 2012-09-24 08:19:03 +02:00 коммит произвёл Greg Kroah-Hartman
Родитель 725ef4a3b6
Коммит 59733ef7e5
1 изменённых файлов: 2 добавлений и 2 удалений

Просмотреть файл

@ -71,7 +71,7 @@ static void cpm_uart_initbd(struct uart_cpm_port *pinfo);
/**************************************************************/
#define HW_BUF_SPD_THRESHOLD 9600
#define HW_BUF_SPD_THRESHOLD 2400
/*
* Check, if transmit buffers are processed
@ -505,7 +505,7 @@ static void cpm_uart_set_termios(struct uart_port *port,
pr_debug("CPM uart[%d]:set_termios\n", port->line);
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
if (baud <= HW_BUF_SPD_THRESHOLD ||
if (baud < HW_BUF_SPD_THRESHOLD ||
(pinfo->port.state && pinfo->port.state->port.tty->low_latency))
pinfo->rx_fifosize = 1;
else