Messages in this thread | | | Date | Fri, 4 Jan 2002 21:20:17 +0100 | From | Vojtech Pavlik <> | Subject | Re: ISA slot detection on PCI systems? |
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On Fri, Jan 04, 2002 at 02:41:46PM -0500, Eric S. Raymond wrote:
> Vojtech Pavlik <vojtech@suse.cz>: > > You'll have to add motherboards that have no ISA slots, but onboard ISA > > devices to the list. > > > > I'd suggest looking at the output of /proc/bus/isapnp as well, because > > if it lists any devices, you certainly need ISA support. > > OK, apparently some people are still confused about what I'm trying to do. > That's no surprise. It confuses *me* sometimes!
I think I understand you. The problem is that many ISA chips (sound, others) that are normally used on ISA cards, and thus handled by drivers most likely labeled by the ISA_CARDS flag, can be, and were often integrated onto mainboards, even if those didn't have any ISA slots.
Think (possibly older generation, like P-MMX based) notebooks ... there you can have
X86 ... true PCI ... true DMI ... true DMI_ISA ... false BLACKLISTED ... possibly true, if you blacklist most notebooks
and yet have many ISA drivers needed for proper operation of the machine.
> > The issue is not ISA support, it is ISA *card* support. At the moment, > and for the foreseeable future, X86 implies ISA. Someday there may be > X86 motherboards without on-board ISA devices, but that's a few years off. > When that does happen, my logic will be something like this, where > PCI_BRIDGE is the test for whether PC reports an ISA bridge. > > X86 and ((PCI and ISA_BRIDGE) or not PCI) => ISA > > The "not PCI" case represents old ISA-only machines. > > What I'm actually trying to do is determine whether the machine can > take ISA *cards*, and use that computation to suppress questions about > ISA cards (probed ones would still be found). For this, the logic > should look as follows, where: > > * DMI means "reports DMI" > * DMI_ISA means "DMI reports ISA slots" > * BLACKLISTED means the motherboard is in an exception list of PCI-supporting, > DMI-supporting motherboards that falsely claim not to have ISA slots. > > X86 and ((not PCI) or (not DMI) or DMI_ISA or BLACKLISTED => ISA_CARDS > > This is one reason I want /sys/dmi -- because if I *don't* see it, that > means I should assume the machine is old enough to take ISA cards. This > filter should make the blacklist relatively small -- we wouldn't have to > track even PCI motherboards older than the DMI standard. > > A key point is that as ISA phases out (near future now), the blacklist > will stop growing. Ballpark guess is it will top out below 150 entries. > -- > <a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a> > > If I were to select a jack-booted group of fascists who are > perhaps as large a danger to American society as I could pick today, > I would pick BATF [the Bureau of Alcohol, Tobacco, and Firearms]. > -- U.S. Representative John Dingell, 1980
-- Vojtech Pavlik SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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