[PATCH] Powerpc 8xx CPM_UART too many interrupts
DORMANTno replies
From: Christophe Leroy <hidden>
Date: 2012-09-24 06:20:31
Also in:
linux-serial, lkml
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 <redacted>
--- linux-3.5-vanilla/drivers/tty/serial/cpm_uart/cpm_uart_core.c 2012-07-21 22:58:29.000000000 +0200
+++ linux-3.5/drivers/tty/serial/cpm_uart/cpm_uart_core.c 2012-08-09 17:38:37.000000000 +0200@@ -71,7 +71,7 @@ /**************************************************************/ -#define HW_BUF_SPD_THRESHOLD 9600 +#define HW_BUF_SPD_THRESHOLD 2400 /* * Check, if transmit buffers are processed
@@ -505,7 +505,7 @@ 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