Date: Thu, 11 Jan 1996 21:02:24 +0100 From: se@zpr.uni-koeln.de (Stefan Esser) To: Bruce Evans <bde@zeta.org.au> Cc: freebsd-hackers@freebsd.org Subject: Re: PnP problem... Message-ID: <199601112002.AA11690@Sysiphos> In-Reply-To: Bruce Evans <bde@zeta.org.au> "Re: PnP problem..." (Jan 12, 0:13)
next in thread | previous in thread | raw e-mail | index | archive | help
On Jan 12, 0:13, Bruce Evans wrote: } Hmm. How do the ISA probes avoid rediscovering PCI/EISA devices? What } happens if there is a "bt0 at isa?" (as specified in the config) on the } ISA bus and another one on the PCI/EISA bus? I think this doesn't work } now. If Neil's approach is used then the corresponding problems are: } How does the config manager know that some ISA devices are physically } the same as a PCI/EISA device? How does the config manager assign } minor numbers in the above complicated case involving bt0 and even in } simple cases? Well, that's easy, actually :) The ISA driver probe will find a conflict with ressources reserved by the earlier PCI probe. This makes the PCI probe win :) And that is the right thing to do, since it is most likely, that the PCI driver will be able to correctly setup interrupts, for example, or it may choose to use memory mapped I/O instead of the traditional port I/O of the ISA variant. Only problem is, that PCI (and EISA ???) drivers don't currently register their ressource usage. But this wouldn't be hard to change ... } 0-0x3ff :-). I think ISA probes will have to be just as invasive as } now except they will be able to be more careful about clobbering } previously probed devices thanks to the more complete resource maps. Well, yes. You never know how many address bits an ISA device actually decodes ... (This might be a prameter to the confict check: let it know, how many address bits the adapter is known to decode (e.g. 10) and make all tests modulo 2^N). Regards, STefan -- Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021 Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160 ============================================================================== http://www.zpr.uni-koeln.de/~se <se@ZPR.Uni-Koeln.DE>
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199601112002.AA11690>