Date: Sun, 16 Jul 1995 12:13:04 -0700 From: "Justin T. Gibbs" <gibbs@freefall.cdrom.com> To: Karl Denninger <karl@mcs.net> Cc: karl@mcs.com, freebsd-hackers@freebsd.org Subject: Re: Twinchannel SCSI Adapter change Message-ID: <199507161913.MAA05283@freefall.cdrom.com> In-Reply-To: Your message of "Sun, 16 Jul 95 13:40:42 CDT." <199507161840.NAA01161@Jupiter.mcs.net>
next in thread | previous in thread | raw e-mail | index | archive | help
>> >Good afternoon, >> > >> >I have changed the probe order on the twin channel SCSI 2742 adapter here t >o >> >probe "b" first. >> > >> >The reason is this: >> > >> >1) "A" has both internal and external connectors. >> >2) "B" has only an internal connector. >> >> I have made modifications to config and the "hard wired" scsiconf code >> that will allow you to do this via the kernel config file. Once I have >> fully tested it, it should go into FreeBSD-current. >> >> -- >> Justin T. Gibbs >> =========================================== >> Software Developer - Walnut Creek CDROM >> FreeBSD: Turning PCs into workstations >> =========================================== > >Uh, I would suggest changing the code in the driver itself to probe in the >opposite sequence. This is what I did here. > >This is a two-line "move the code" change, and since it requires no actual >changes to the operational status of the software, is much safer from a >testing perspective. It also requires no changes to the "hardwired" side >of things. I know what the necessary change is (I wrote the driver after all), and I've done similar things for machine that needed to probe in the reverse order. Unfortunately, the hard wired SCSI device code does not handle controllers that have more than one bus correctly since you should be able to hardwired the busses in reverse, so I'd rather use this more general method. >You just set "B" as the primary channel in the EISA configuration. > >Actually, an *IDEAL* implementation would look at the state of the primary >channel bit in the EISA configuration and decide from that which to probe >first. It *IS* in there for boot control. Unfortuantely, I don't know how to get to this information once FreeBSD has booted otherwise the probe order would be determined in this fashion. >Frankly, I'm surprised that Adaptec didn't designate the internal-only >connector as "A" instead of "B". It makes more sense. Not if most people never use the B channel. >-- >Karl Denninger (karl@MCS.Net)| MCSNet - The Finest Internet Connectivity >Modem: [+1 312 248-0900] | (shell, PPP, SLIP, leased) in Chicagoland >Voice: [+1 312 248-8649] | 7 Chicagoland POPs, ISDN, 28.8, much more >Fax: [+1 312 248-9865] | Email to "info@mcs.net" WWW: http://www.mcs.net >ISDN - Get it here TODAY! | Home of Chicago's only FULL AP Clarinet feed! -- Justin T. Gibbs =========================================== Software Developer - Walnut Creek CDROM FreeBSD: Turning PCs into workstations ===========================================
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199507161913.MAA05283>