On Fri, Dec 14, 2007 at 07:51:06AM +1100, Benjamin Herrenschmidt wrote: > If the device is behind a P2P bridge and the BIOS has set the windows of > that bridge so tightly that there is no room to allocate the MMIO BAR, > then a full disable/full enable would fail on a device that would > otherwise work using only PIO.
It won't be a problem with separate io/mmio enable. > However, I'd be curious to see that happening in practice :-) > > But I think it's fair enough to do an IO only / MEM only approach. I've > seen cases where IO is just not useable because of other constraints and > so I expect the MEM-only case to be more common, especially on non-x86. Everybody wants MEM if it's available - it's just faster :-) So I guess a common case will be if (pci_enable_device_mmio(dev)) { /* failed, fallback to IO */ if (pci_enable_device_io(dev)) return -ENODEV; ... } Ivan. -- 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/