Re: [RFC PATCH v5 7/8] PCI/PCIe: add "pci=nopciehp" to disable PCIe native hotplug

[Rafael J. Wysocki]

On Friday, January 18, 2013 10:35:46 AM Bjorn Helgaas wrote:
> 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 .
> 
> 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.

And one can use pcie_ports=compat to work around these problems anyway.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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