On Mon, 23 Sep 2013, Andy Lutomirski wrote: > I've been getting this on several recent kernel revisions. Is it > interesting? If so, I'm happy to help diagnose it. If not, can the > message be killed or severely ratelimited? I'm getting so much of > this that it tends to overflow the log ring. It's interesting only if you care about when your EHCI controllers get resumed and suspended. In this case, it's not clear why the transitions happen so rapidly. It looks like some sort of polling is going on at roughly 2-second intervals. > [ 287.344991] ehci-pci 0000:00:1d.0: power state changed by ACPI to D0 > [ 287.445433] ehci-pci 0000:00:1d.0: setting latency timer to 64 > [ 287.446255] ehci-pci 0000:00:1a.0: power state changed by ACPI to D0 > [ 287.456094] ehci-pci 0000:00:1d.0: power state changed by ACPI to D3cold > [ 287.547205] ehci-pci 0000:00:1a.0: setting latency timer to 64 > [ 287.557890] ehci-pci 0000:00:1a.0: power state changed by ACPI to D3cold > [ 290.126910] ehci-pci 0000:00:1d.0: power state changed by ACPI to D0 > [ 290.227958] ehci-pci 0000:00:1d.0: setting latency timer to 64 > [ 290.228416] ehci-pci 0000:00:1a.0: power state changed by ACPI to D0 > [ 290.238749] ehci-pci 0000:00:1d.0: power state changed by ACPI to D3cold > [ 290.328904] ehci-pci 0000:00:1a.0: setting latency timer to 64 > [ 290.339565] ehci-pci 0000:00:1a.0: power state changed by ACPI to D3cold > [ 292.214834] ehci-pci 0000:00:1d.0: power state changed by ACPI to D0 > [ 292.315458] ehci-pci 0000:00:1d.0: setting latency timer to 64 > [ 292.315908] ehci-pci 0000:00:1a.0: power state changed by ACPI to D0 > [ 292.326262] ehci-pci 0000:00:1d.0: power state changed by ACPI to D3cold > [ 292.416487] ehci-pci 0000:00:1a.0: setting latency timer to 64 > [ 292.431075] ehci-pci 0000:00:1a.0: power state changed by ACPI to D3cold > [ 295.458048] ehci-pci 0000:00:1d.0: power state changed by ACPI to D0 > [ 295.558613] ehci-pci 0000:00:1d.0: setting latency timer to 64 This question should be addressed to the PCI mailing list (cc'ed), as those two messages are generated by drivers/pci/pci-acpi.c:acpi_pci_set_power_state() and drivers/pci/pci.c:pcibios_set_master() respectively. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
