Date: Wed, 06 May 1998 15:19:26 -0700 From: Mike Smith <mike@smith.net.au> To: Nate Williams <nate@mt.sri.com> Cc: Amancio Hasty <hasty@rah.star-gate.com>, Mike Smith <mike@smith.net.au>, Archie Cobbs <archie@whistle.com>, stefan@promo.de (Stefan Bethke), luigi@labinfo.iet.unipi.it, freebsd-hackers@FreeBSD.ORG Subject: Re: ISA-PnP w\o BIOS support? Message-ID: <199805062219.PAA00563@antipodes.cdrom.com> In-Reply-To: Your message of "Wed, 06 May 1998 10:43:29 MDT." <199805061643.KAA16376@fly.mt.sri.com>
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> > The device driver can tell the upper layer which resources it wants or > > does not need. > > The device driver needs a hint from the user to know whether or not it > wants a resource or not. Sure. Stick a sysctl variable in there. I have commandline sysctl setting working from userconfig, and I'm about half done with the visual version. > For example, some PCIC controllers don't correctly interrupt when cards > are removed/inserted. In this case, we still assign an IRQ to the > controller, although all we're doing is wasting an interrupt. Instead > of assigning an interrupt, we should simply 'poll' the controller for > events, which doesn't work as well *but* still allows the hardware to > work. > > However, the FreeBSD kernel can't determine if the controller is > working, so we need a way for the controller probe to be given 'hints' > as to whether or not to use an IRQ, and if so a good one to try. The > latter is needed because some 'internal' hardware is hidden from the > kernel, so if I use the first free interrupt it *may* not be correct for > this configuration, so I must tell it which interrupt to use if I want > to be safe. The principal issue with using the PnP BIOS is that all of a sudden, the "hidden" hardware is revealed. This makes it impossible to assign a resource that is already allocated. > In other words, the device driver does *NOT* have enough information to > do it's job, hence the current model is incomplete. The current current model, yes. The proposed model, no. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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