On Thu, 29 Aug 2013, Martin MOKREJŠ wrote: > Alan Stern wrote: > > On Thu, 29 Aug 2013, Martin MOKREJŠ wrote: > > > >> Hi Xenia, > >> thank you, how about inclusion of the "parent hub" number in the > >> following message (as of now): > >> > >> Parent hub missing LPM exit latency info. Power management will be impacted. > >> > >> > >> > >> I find it awkward to later on run manually lspci/lsusb to find what is the parent. > > > > You don't need to run those programs. > > > >> I think I do NOT get these messages when I have pcie_aspm=off whereas when > >> it is on I get the warning. Why PCIe powersaving affects how USB end devices will > >> be put to sleep I don't know. But that will be the next step to look into. > >> First the warning message. And maybe it could be improve even further to include > >> other relevant capabilities of the "parent" present/missing. ;-) > >> > >> > >> Here are bits from my dmesg: > > > >> [ 5.291321] usb 4-2: new SuperSpeed USB device number 2 using xhci_hcd > >> [ 5.313219] usb 4-2: Parent hub missing LPM exit latency info. Power management will be impacted. > > > > Since this device is 4-2, the parent hub is usb4. > > Hmm, and it's corresponding PCI device? I know, not always the case but ... The correspondence between a USB bus and the controller's PCI device path is harder to figure out. You can't get it from lspci or lsusb -- although you can get it (with a little difficulty) from "lsusb -v". Perhaps the easiest way to do it is simply with ls: $ ls -l /sys/bus/usb/devices/usb1 lrwxrwxrwx 1 root root 0 Aug 29 09:48 /sys/bus/usb/devices/usb1 -> ../../../devices/pci0000:00/0000:00:1d.7/usb1/ The 0000:00:1d.7 embedded near the end of the output is the controller's PCI address. Note, however, that the change you asked Ksenia to perform (printing the parent hub's name) won't give you the PCI device. In your case, for instance, it would simply print "usb4". 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
