On Tue, 2014-07-29 at 10:30 -0600, Keith Busch wrote: > On Tue, 29 Jul 2014, Alex Williamson wrote: > > On Tue, 2014-07-29 at 16:17 +0800, Yijing Wang wrote: > >> Currently we don't update device's mps value when doing > >> pci device hot-add. The hot-added device's mps will be set > >> to default value (128B). But the upstream port device's mps > >> may be larger than 128B which was set by firmware during > >> system bootup. In this case the new added device may not > >> work normally. > > > > Apologies if we rehash some previously discussed topics while I try to > > cover for Bjorn while he's out. By "normally", do you mean "optimally"? > > The device should be functional with a lower mps setting, right? > > You'd think so, but some platforms don't work. A pci-e trace showed > TLPs exceeding MPS when parent device at 256B and the end device left > at 128B. Even if that's a platform bug, I think we still want it to work. But if it's a platform bug for a non-compliant device, should it be handled as a quirk rather than standard configuration? Thanks, Alex -- 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
