From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10386 invoked by alias); 16 Jan 2006 15:13:29 -0000 Received: (qmail 10377 invoked by uid 22791); 16 Jan 2006 15:13:28 -0000 X-Spam-Check-By: sourceware.org Received: from omr6.networksolutionsemail.com (HELO mail.networksolutionsemail.com) (205.178.146.56) by sourceware.org (qpsmtpd/0.31) with SMTP; Mon, 16 Jan 2006 15:13:25 +0000 Received: (qmail 24800 invoked from network); 16 Jan 2006 15:13:23 -0000 Received: from unknown (HELO rivatek.dnsalias.net) (67.52.40.201) by omr6.mgt.bos.netsol.com with SMTP; 16 Jan 2006 15:13:23 -0000 Received: by rivatek.dnsalias.net (Postfix, from userid 501) id 0E23B3CAC0; Mon, 16 Jan 2006 09:17:04 -0600 (CST) To: ecos-discuss@ecos.sourceware.org From: Grant Edwards In-Reply-To: <87vewklg60.fsf@ebbot.hq.sigicom.net> References: <87vewklg60.fsf@ebbot.hq.sigicom.net> Date: Mon, 16 Jan 2006 15:13:00 -0000 Message-Id: <20060116151704.0E23B3CAC0@rivatek.dnsalias.net> Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: [ECOS] Re: DSR Scheduling Problem X-SW-Source: 2006-01/txt/msg00128.txt.bz2 >>> If the transmitter has a hardware FIFO, and the software >>> transmits one byte per interrupt, >> >> Then the sofware is completely and utterly broken. It doesn't >> deserve to work. >> >>> then presenting a block of data to it after an idle period >>> will invoke the ISR/DSR a slew of times until the FIFO is >>> full. >> >> That's insane. Nobody with a clue would write software like >> that. > > Actually, the generic 16x5x serial driver in eCos works > exactly like that. You're kidding! >> When you get a TX interrupt you write data to the tx FIFO until it's >> full. > > Yep. I've made a somewhat quick-and-dirty fix that is attached below. That should provide a drastic reduction in load for that driver. -- Grant Edwards grante Yow! FIRST, I'm covering at you with OLIVE OIL and visi.com PRUNE WHIP!! -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss