From owner-freebsd-hardware Tue May 20 21:05:11 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id VAA15449 for hardware-outgoing; Tue, 20 May 1997 21:05:11 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id VAA15443 for ; Tue, 20 May 1997 21:05:03 -0700 (PDT) Received: (from msmith@localhost) by genesis.atrad.adelaide.edu.au (8.8.5/8.7.3) id NAA08585; Wed, 21 May 1997 13:34:41 +0930 (CST) From: Michael Smith Message-Id: <199705210404.NAA08585@genesis.atrad.adelaide.edu.au> Subject: Re: isa bus and boca multiport boards In-Reply-To: <3.0.1.32.19970520125159.006dbe70@lariat.org> from Brett Glass at "May 20, 97 12:51:59 pm" To: brett@lariat.org (Brett Glass) Date: Wed, 21 May 1997 13:34:41 +0930 (CST) Cc: rberndt@nething.com, WELCHDW@wofford.edu, HARDWARE@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL28 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hardware@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Brett Glass stands accused of saying: > At 04:14 PM 5/20/97 -0400, you wrote: > > Maybe the sio driver should be recoded in optimized ASM. I can see some > major C inefficiencies in it, including lots of repeated pointer > dereferences and control structures that the compiler would probably > optimize poorly. I've generated super-tight assembler for serial I/O. (cocks an ear listening for the ICBM leaving bde's desk). I don't think that would be a very popular idea; the sio driver should be more, not less, machine independant. > A stopgap might be be use a couple of IRQs for the different ports, if the > board lets you do it. I put no more than 4 UARTs on an IRQ in my system > because the driver loops over the UARTS at least twice per IRQ. The boards in question don't. FWIW, the ISP across the hall from my office has a 386dx40 with an 8-port PC-COM (AST-alike) card and four single UARTs; it gets beaten to death and beyond using a mix of iijppp and SLiRP and keeps up quite happily. There's nothing basically wrong with the sio driver in that regard. > --Brett -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[