On Tue, 2007-03-20 at 13:26 -0700, Greg KH wrote: > On Tue, Mar 20, 2007 at 01:25:38PM -0400, Daniel Yeisley wrote: > > On Tue, 2007-03-20 at 11:00 -0700, Greg KH wrote: > > > On Tue, Mar 20, 2007 at 12:18:24PM -0400, Daniel Yeisley wrote: > > > > It has been mentioned before that large systems with a lot of PCI buses > > > > have issues with the 64k I/O space limit. The ES7000 has a BIOS option > > > > to either assign I/O space to all adapters, or only to those that need > > > > it. A list of supported adapters that don't need it is kept in the > > > > BIOS. When this option is used, the kernel sees the BARs on the > > > > adapters and still tries to assign I/O space (until it runs out). I've > > > > written a patch to implement a boot parameter that tells the kernel not > > > > to assign I/O space if the BIOS hasn't. > > > > > > How prelevant are machines like this? And why are the BARs on these > > > devices wrong? > > > > > I don't have any sales numbers, but I can tell you that our current > > systems can have up to 64 PCI buses. > > > > I've been working with Emulex cards, and my understanding is that the > > BARs on the devices aren't wrong, but we can't allocate 4k of I/O space > > for each one. So we maintain a list in the BIOS of devices that don't > > actually need I/O space and then don't assign it. I've tested an a > > x86_64 system with 20+ adapters and saw all the disks attached without > > any problems. > > Ah. Others are working on providing a fix for this too, but it is being > done in the drivers themselves, not in the pci core. Look in the > linux-pci mailing list archives for those patches (I don't think they > every went into mainline for some reason, but I might be wrong...) > > I suggest you work with those developers, as they have the same issue > that you are trying to solve here. >
I have seen some patches that make the drivers I/O port free here: http://lkml.org/lkml/2006/2/26/261 I checked and they still aren't in the mainline. I don't know that it matters though because I see all the disks attached to the system regardless of whether or not the adapters get I/O space. The real issue I have is with all the error messages I get at boot. I see 40+ messages that say "PCI: Failed to allocate I/O resource..." (from setup-res.c) when the kernel tries to allocate the I/O space and can't. The modules load fine. I see all the disks just fine. But that many error messages tends to raise concerns and causes support calls from customers. Dan - 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/
