Ivan Kokshaysky wrote: > On Wed, Sep 26, 2007 at 03:20:40PM -0700, Jesse Barnes wrote: >> Ivan, your concern is about disabling things like interrupt controllers >> and power management chips during probe right? You're right that doing >> that could cause problems if we get and interrupt or PMU event at just >> the wrong time, but that could just as easily happen if decode was >> still enabled but the BAR had a bogus address programmed (as it would >> during probing). > > Yes, nobody is arguing that moving the BAR around is unsafe, but generally > it's the less of two evils. > > The major problem here is that with IO and MEM bits cleared in the command > register you disable *all* address decoders on the device, not just ranges > that have respective BARs. At least this behaviour is required by PCI spec. > Examples: > - legacy VGA IO and memory (no corresponding BARs); > - base/limit registers of P2P bridge; > - PMU and SMBus registers (sort of normal BARs, but hidden elsewhere > in the config space); > - IDE legacy mode registers; > - IO-APIC registers (typically sort of read-only BAR). > > For all of these address ranges our current BAR probe is effectively > a no-op, but disable/re-enable clearly isn't. > >> Ultimately, I don't care much one way or another as long as we can get >> the desktop platforms fixed somehow. I think disabling decode is the >> most correct way of doing this, but I'm open to other solutions (this >> is the only patch I've seen though that's been tested to solve the >> problem). > > There are two other solutions: one is to disable decode selectively, > only on devices or systems where it's necessary and known to be safe. > I've posted a patch which introduces "disable_while_probe" pci_dev field > for that purpose. > Another one is to delay mmconfig probe until after the PCI probe is done, > as Matthew suggested, and Robert confirmed that it's feasible.
for everyone who's using this quirk or has the same boot issue: I just confirmed that the new dg33tl bios update v0287 (released 9/20) fixes the boot issue for my systems. I encourage everyone to update their BIOS image and see if this works. Cheers, Auke - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/