On Fri, Jul 22, 2016 at 10:15:46AM -0500, Bjorn Helgaas wrote: > Hi Bharat, > > On Fri, Jul 22, 2016 at 09:24:22AM +0000, Bharat Kumar Gogada wrote: > > Hi, > > > > I'm observing that on x86 BIOS successfully assigns memory if an End point requests > > BAR of size 16byte. > > > > But as per Spec: > > The minimum memory address range requested by a BAR is 128 bytes. > > Can you provide the spec reference for this? I don't see it in PCI > r3.0. > > PCI r3.0, sec 6.2.5.1, shows bits 4-31 of a memory BAR as writable, > which would correspond to a minimum size of 16 bytes. The reference above is to the conventional PCI spec. I happened to trip over a note in PCIe r3.0, sec 1.3.2.2, that for a PCI Express endpoint, "the minimum memory address range requested by a BAR is 128 bytes." I don't think linux currently enforces this minimum. 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
