Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 23 Dec 1999 23:25:50 -0800
From:      Mike Smith <msmith@freebsd.org>
To:        Joe McGuckin <joe@via.net>
Cc:        hackers@freebsd.org
Subject:   Re: motherboard serial port dropping chars ? 
Message-ID:  <199912240725.XAA02292@mass.cdrom.com>
In-Reply-To: Your message of "Mon, 20 Dec 1999 20:23:11 PST." <199912210423.UAA76829@monk.via.net> 

next in thread | previous in thread | raw e-mail | index | archive | help
> 
> I have an application where I need to receive data constantly on
> a serial port at 38,400. When we write the data to a database,
> we constantly see dropped chars on the incoming serial port.
> 
> Is the stock PC serial hardware capable of sustained thruput at
> 38.4K?  

Easily, modulo other peripherals which can interfere with this.

> Is there an ioctl option or something to improve the buffering
> on the serial ports ?

No.  You probably have a PCI peripheral that's hogging the bus for 
sufficiently long to cause the FIFO in your serial device to overflow.  
IDE disks doing DMA are prime culprits for this, and X servers have been 
known to cause it as well (by disabling interrupts entirely).

-- 
\\ Give a man a fish, and you feed him for a day. \\  Mike Smith
\\ Tell him he should learn how to fish himself,  \\  msmith@freebsd.org
\\ and he'll hate you for a lifetime.             \\  msmith@cdrom.com




To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199912240725.XAA02292>