From owner-freebsd-hackers Fri Jun 2 16:19:46 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id QAA28301 for hackers-outgoing; Fri, 2 Jun 1995 16:19:46 -0700 Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.97.216]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id QAA28287 for ; Fri, 2 Jun 1995 16:19:41 -0700 Received: (from kargl@localhost) by troutmask.apl.washington.edu (8.6.11/8.6.9) id QAA04237; Fri, 2 Jun 1995 16:14:35 -0700 From: Steven G Kargl Message-Id: <199506022314.QAA04237@troutmask.apl.washington.edu> Subject: Re: 3c509 and modems? To: erich@rrnet.com (Eric L. Hernes) Date: Fri, 2 Jun 1995 16:14:34 -0700 (PDT) Cc: freebsd-hackers@freefall.cdrom.com In-Reply-To: from "Eric L. Hernes" at Jun 2, 95 06:13:30 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1214 Sender: hackers-owner@FreeBSD.org Precedence: bulk According to Eric L. Hernes: > > > Maximum modem speed allows the 3c509 to disable interrupts for various > > lengths of time. If you have a fast modem (or serial device), then you > > do not want the interrupts disabled for long time periods. If on the > > other hand you have slow serial devices, the interrupts can be disabled > > for a longer time period, and thus improving the performance of the > > 3c509. > > does this happen at the hardware level? > I thought that spl*() and splx() were for handling just such events. > What should this be set to to disable this bug. > (making the hardware compensate for the OS's shortcoming's is a bug in > my opinion.) > Good question. Judging from the few comments in the Adapter Guide, I am incline to believe that the maximum modem speed is for optimization of the software drivers provided by 3com (and it is stored in eprom). I am not very familiar with the FreeBSD driver, so you're probably correct that spl*() handles this. -- Steven G. Kargl | Phone: 206-685-4677 | Applied Physics Lab | Fax: 206-543-6785 | Univ. of Washington |---------------------| 1013 NE 40th St | FreeBSD 2.1-current | Seattle, WA 98105 |---------------------|