How to know if you are affected [LWN.net]

How to know if you are affected

Posted Jun 29, 2011 18:12 UTC (Wed) by troy.unrau (guest, #73654)
In reply to: How to know if you are affected by cesarb
Parent article: PCIe, power management, and problematic BIOSes

So my dmesg did indeed report this on my HP G60 series lappy... seemed like a good idea to ruin my uptime to try the boot parameter... So upon reboot, I get:

# dmesg | grep ASPM
[ 0.000000] PCIe ASPM is forcedly enabled
[ 0.439490] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it

I'm not sure this means that the kernel has decided to turn it off anyway, or if my laptop truly doesn't support it. Still need more data to determine if power drain improves.

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How to know if you are affected

Posted Jun 29, 2011 18:18 UTC (Wed) by cesarb (subscriber, #6266) [Link]

Looking at the patch, it always prints that, then it calls the new pcie_clear_aspm() function, which only does its work if you did not force it:

+void pcie_clear_aspm(void)
+{
+ if (!aspm_force)
+ aspm_clear_state = 1;
+}

How to know if you are affected

Posted Jun 29, 2011 18:30 UTC (Wed) by mjg59 (subscriber, #23239) [Link]

Yes, you can ignore the message in that case. I should probably fix that.