Re: /sys/module/pcie_aspm/parameters/policy not writable?

From: Bjorn Helgaas
Date: Thu Aug 01 2013 - 16:27:54 EST

On Thu, Aug 1, 2013 at 2:00 PM, Pavel Machek <pavel@xxxxxx> wrote:
> Hi!
>> > But since the problem also occurs with Windows, it's pretty likely
>> > that there's a BIOS update to fix it. I notice on the X60 support
>> > page that there are several versions newer than what you're running.
>> Do you have any interest in trying a newer BIOS to see if it's fixed
>> there? If not, I understand; BIOS updates are a hassle at best.
>> You're running BIOS 2.14, and it looks like the current BIOS for an
>> X60 1709 7HU is 2.19 (from
> I'm lost at the lenovo pages :-(. And frankly I'd prefer not to touch
> the BIOS.

I tried to provide a complete link, but the web site isn't amenable to
that. I found it by selecting the "Drivers & Software" section,
entering "X60" as the machine type, selecting "ThinkPad X60 (1709)"
and going to the "BIOS" section. I was surprised how easy it was :)

>> Carolyn's patch will likely work, at least most of the time, but I
>> think there's a small possibility that it could cause a conflict
>> between the BIOS and the OS over ASPM control, so I'm not 100% in
>> support of that approach. A conflict may not happen on your
>> machine,
> Can we base it on DMI whitelist?

I don't think we can know a priori whether a machine (even your
machine) is susceptible to a conflict. But if Carolyn forcibly
disables it in the driver, she can structure that with a whitelist or
whatever she thinks is best.

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