On Monday 22 March 2010 02:21:35 pm Dominik Brodowski wrote: > Hey, > > On Mon, Mar 22, 2010 at 01:08:35PM -0700, Bjorn Helgaas wrote: > > > So, what should we do? > > > > Let's back up a bit. I don't know enough about PCMCIA, and I don't > > see the problem yet. We have the 00:1e.0 bridge leading to bus 04, > > and 04:06.0 is a CardBus bridge. These three windows are the ranges > > positively decoded and forwarded by the 00:1e.0 bridge: > > > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge I/O window: 0x1000 - 0x1fff > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge Memory window: 0xd2000000 - 0xd40fffff > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge Memory window: 0xd0000000 - 0xd1ffffff > > > > But the bridge is in subtractive-decode mode, so it *also* forwards > > anything it sees that is unclaimed by other devices on bus 00, which > > means the 04:06.0 CardBus bridge will also see these ranges: > > > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge I/O window: 0x0 - 0xcf7 > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge I/O window: 0xd00 - 0xffff > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge Memory window: 0xa0000 - 0xbffff > > yenta_cardbus 0000:04:06.0: pcmcia: parent PCI bridge Memory window: 0xc0000000 - 0xfebfffff > > > > Why do you care whether these additional ranges are excluded? They > > should be just as usable as the first three. > > Quoting rsrc_nonstatic.c: > > /* If this is the root bus, the risk of hitting > * some strange system devices which aren't protected > * by either ACPI resource tables or properly requested > * resources is too big. [...] > */ > > Or, as Alan put it -- when it came to I/O resources in the 0x100-0x3ff area: > > "Which crashes older thinkpads, some ATI chipset systems and > usually anything containing an NE2000 clone in ISA space." > > You can still use subtractive-decoded resources, but then you have to add > them to /etc/pcmcia/config.opts and run pcmcia-startup-bridges (or echo the > resource to a sysfs file). It's too bad we still have such manual configuration. Is there still information there that we can't figure out automatically? > Now, "usecrs" is only used on 2008-or-newer systems where we _hope_ that all > resource "consumers" are accounted for. So the problem might be mitigated. > However, I wouldn't dare to use ioports 0x0-0xff anyways for they usually > are used for onboard legacy devices... Right. But PCMCIA is at no greater risk than regular PCI, right? It looks like both will allocate only above PCIBIOS_MIN_IO (0x1000). Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
