From mboxrd@z Thu Jan 1 00:00:00 1970 To: Dan Malek Cc: "Brown, David (dbrown03)" , linuxppc-embedded@lists.linuxppc.org Subject: Re: Is it normal for serial ports to drop characters at the end? References: <391083CC.7E08CC54@embeddededge.com> From: Marcus Sundberg Date: 03 May 2000 22:05:37 +0200 In-Reply-To: Dan Malek's message of "Wed, 03 May 2000 15:53:48 -0400" Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Dan Malek writes: > Marcus Sundberg wrote: > > > Right on target. > > rs_8xx_wait_until_sent() will wait for the *first* buffer descriptor > > to be finished, instead of waiting for the last one as it should. > > This patch fixes that problem: > > That's part of it, but we also need to perform a graceful shutdown > of the port so we wait until the hardware FIFOs are empty. Waiting > for the buffer descriptor just means the CPM moved the last data > from the buffer, not that it has gone out the wire. Sure, but the above "works perfect for me(tm)", at least in 9600bps. > I thought I did this once.....but, why are you closing devices anyway :-). I think I experienced this first when using the busybox init implementation, which IIRC opens and closes /dev/console for each message. Otherwise I've never seen it in a real application. /Marcus -- -------------------------------+----------------------------------- Marcus Sundberg | Phone: +46 707 452062 Embedded Systems Consultant | Email: marcus@cendio.se Cendio Systems AB | http://www.cendio.com ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/