Re: [PATCH] PCI: Remove not needed check in disable aspm link

From: Yinghai Lu
Date: Fri Jun 14 2013 - 12:57:36 EST


On Fri, Jun 14, 2013 at 9:33 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
> On Fri, Jun 14, 2013 at 10:17 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>
> Can you please refer to specific function names? I can't read your mind.
>
> You might be referring to quirk_disable_aspm_l0s(). This is a
> pci_fixup_final quirk that calls pci_disable_link_state(). In the
> current tree, we enumerate devices before requesting _OSC control.
> However, pci_fixup_final quirks are not run until the
> pci_apply_final_quirks() fs_initcall, which is after we request _OSC
> control.
>
> As far as I can tell, we never call pci_disable_link_state() before
> calling pcie_no_aspm().

ok, you are right, that is not pci_disable_link_state.

It is pcie_aspm_init_link_state ==> pcie_aspm_sanity_check in booting path
that disable aspm. It has "if (aspm_disabled)" in it, and it cause
the difference.

Yinghai
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