On Sat, Jan 19, 2013 at 09:56:24AM +0800, Yijing Wang wrote: > 于 2013-01-19 1:35, Bjorn Helgaas 写道: > > On Fri, Jan 18, 2013 at 9:07 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote: > >> If user specifies "pci=nopciehp" on kernel boot command line, OSPM > >> won't claim PCIe native hotplug service from firmware and no PCIe > >> port devices will be created for PCIe native hotplug service. > > > > Why do we need this option? > > > > If I understand correctly, there are machines where it *looks* like we > > should use pciehp, but pciehp doesn't work because we don't get the > > interrupts we expect. On those machines, we have to use acpiphp > > instead. It seems like many Dell XPS laptops have this issue with > > ExpressCard slots, e.g., > > https://bugzilla.kernel.org/show_bug.cgi?id=40802 . > > What about use modprobe pciehp pciehp_poll_mode=1? > If just cannot receive the interrupt, maybe this module parameter will fix it. You can't add a new option that you now force hardware that was working with a different module to now define and use. It needs to be "automatic". > > If you want "pci=nopciehp" as a way for users to deal with this > > problem by forcing the use of acpiphp, I object. Windows manages to > > make these slots work without having users do anything special, so we > > should be able to do it, too. > > In fact, pcie native hotplug may not be implemented perfectly, Oh, we know that is true, it's the problem here. Fixing BIOSes would be nice, but we can't do that :( greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
