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.
Actually, even if that would be a another USB HUB and not a PCI device (root hub),
I would be happy if it extracted something like:
Bus 004 Device 006: ID 2109:0810 $iManufacturer and $iProduct
for me.
Bus 004 Device 006: ID 2109:0810
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 3
bMaxPacketSize0 9
idVendor 0x2109
idProduct 0x0810
bcdDevice 3.74
iManufacturer 1 VIA Labs, Inc.
iProduct 2 4-Port USB 3.0 Hub
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 31
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 2mA
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