From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: David Presotto To: 9fans@cse.psu.edu Subject: Re: [9fans] Re: random moving of cursor arrow In-Reply-To: <29ce300d69819f673d96bbd7d9ae9302@vitanuova.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="upas-ueohervfasvaxjinsugzewvztl" Date: Sat, 26 Jul 2003 11:37:42 -0400 Topicbox-Message-UUID: 046845ec-eacc-11e9-9e20-41e7f4b1d025 This is a multi-part message in MIME format. --upas-ueohervfasvaxjinsugzewvztl Content-Disposition: inline Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit We had a long history of 16[54]xx chips with buggy fifos and/or unchangeable length fifos. At 1200 baud, these guys used to delay mouse actions 1/7 of a second during a sweep and as much as 1/4 second at the end of the sweep. The sweep delay was barely perceptible but the mouse movement just as you were taking your hand off the mouse bothered people. We had similar problems with uarts on MIPS/SGI machines. All those machines should have died years ago, but since I don't normally use a serial port mouse (all ours are PS/2) I just haven't bothered. I'll make fifo on the default for serial mice. However, that really doesn't explain what's going on. Unless the people seeing these problems are on sub 100 megahz machines, we're really screwing up if we can't keep up with 120 or 240 interrupts per second. Something must have broken when we changed to a common model for all the uarts (or changed the scheduler). I'll go into work today and bang at some machines and see if I can recreate/fix the problem. I'm back for a way or two to rest up and serial ports are about as restful as it gets. --upas-ueohervfasvaxjinsugzewvztl Content-Type: message/rfc822 Content-Disposition: inline Received: from plan9.cs.bell-labs.com ([135.104.9.2]) by plan9; Sat Jul 26 04:34:31 EDT 2003 Received: from mail.cse.psu.edu ([130.203.4.6]) by plan9; Sat Jul 26 04:34:28 EDT 2003 Received: by mail.cse.psu.edu (CSE Mail Server, from userid 60001) id 0EDFB19C76; Sat, 26 Jul 2003 04:34:20 -0400 (EDT) Received: from psuvax1.cse.psu.edu (psuvax1.cse.psu.edu [130.203.6.6]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id E4CB619A98; Sat, 26 Jul 2003 04:34:15 -0400 (EDT) X-Original-To: 9fans@cse.psu.edu Delivered-To: 9fans@cse.psu.edu Received: by mail.cse.psu.edu (CSE Mail Server, from userid 60001) id 8598E19B68; Sat, 26 Jul 2003 04:33:40 -0400 (EDT) Received: from doppio.vitanuova.com (unknown [62.254.170.97]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id A7F3619AA4 for <9fans@cse.psu.edu>; Sat, 26 Jul 2003 04:33:37 -0400 (EDT) Message-ID: <29ce300d69819f673d96bbd7d9ae9302@vitanuova.com> From: C H Forsyth To: 9fans@cse.psu.edu Subject: Re: [9fans] Re: random moving of cursor arrow In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: 9fans-admin@cse.psu.edu Errors-To: 9fans-admin@cse.psu.edu X-BeenThere: 9fans@cse.psu.edu X-Mailman-Version: 2.0.11 Precedence: bulk Reply-To: 9fans@cse.psu.edu List-Id: Fans of the OS Plan 9 from Bell Labs <9fans.cse.psu.edu> List-Archive: Date: Sat, 26 Jul 2003 09:37:12 +0100 X-Spam-Status: No, hits=-0.5 required=5.0 tests=IN_REP_TO version=2.55 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) >>I used to avoid the fifo for mice because it made the mouse jerky. i never really understood that: i switched on the uart fifo at the start on a system i did and it handled a mouse without fuss. --upas-ueohervfasvaxjinsugzewvztl--