Re: How to avoid serial port buffer overruns?
From: Russell King
Date: Thu Aug 17 2006 - 05:25:49 EST
On Thu, Aug 17, 2006 at 10:20:46AM +0100, Alan Cox wrote:
> Ar Iau, 2006-08-17 am 00:10 +0100, ysgrifennodd Russell King:
> > MIDI uses its own driver - sound/drivers/serial-u16550.c. My guess
> How peculiar
> > is there's something in the system starving interrupt servicing.
> > Serial is very sensitive to that, and increases in other system
> > latencies tends to have an adverse impact on serial.
> I see no support for the 16650 specific bits in the driver, so that
> alone may be a problem ?
Huh? 16550 not 16650. Did you miss this?
outb(UART_FCR_ENABLE_FIFO /* Enable FIFO's (if available) */
| UART_FCR_CLEAR_RCVR /* Clear receiver FIFO */
| UART_FCR_CLEAR_XMIT /* Clear transmitter FIFO */
| UART_FCR_TRIGGER_4 /* Set FIFO trigger at 4-bytes */
/* NOTE: interrupt generated after T=(time)4-bytes
* if less than UART_FCR_TRIGGER bytes received
,uart->base + UART_FCR); /* FIFO Control Register */
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
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