On Wed, May 24, 2017 at 12:43 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Output of `cat /sys/kernel/debug/usb/usbmon/1u`:
>> Runtime PM disabled as attachment.
>
> When you say "runtime PM disabled", you mean that it is disabled for
> the EHCI controller but enabled for other devices, right?
Yes, disabled for the ehci-hcd. Runtime PM is enabled for ehci-pci.
>
>> It's empty when runtime PM is enabled.
>
> And nothing shows up in the dmesg log either? This suggests that the
> PME signal isn't working properly.
>
> Try doing this: With runtime PM enabled, plug in a device. When
> nothing happens, do:
>
> lspci -v -s 00:12.0
>
> The output should show whether the controller is sending a wakeup
> signal. Does it cause the device to be detected?
No.
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB
EHCI Controller (rev 39) (prog-if 20 [EHCI])
Subsystem: Dell FCH USB EHCI Controller
Flags: 66MHz, medium devsel, IRQ 18
Memory at fe769000 (32-bit, non-prefetchable) [size=256]
Capabilities: [c0] Power Management version 2
Capabilities: [e4] Debug port: BAR=1 offset=00e0
Kernel driver in use: ehci-pci
> If it doesn't, run lsusb. That definitely should wake up the
> controller and cause the device to be detected. Then run the lspci
> command again. Let's see what the output from these commands shows.
I plugged an optical mouse to test:
lsusb or "lsusb -s 001:001" does nothing, the mouse is not shown in
lsusb. The optical light is off.
"lsusb -s 001:001 -v" wakes up the controller and make the mouse to be
detected, the mouse is in lsusb and works correctly.
Once I turned on runtime PM on the mouse, it no longer works. The
optical light is still on but it did not response to movement or
click.
This is the lspci right after I use "lsusb -s 001:001 -v" to wake up
the controller:
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB
EHCI Controller (rev 39) (prog-if 20 [EHCI])
Subsystem: Dell FCH USB EHCI Controller
Flags: bus master, 66MHz, medium devsel, latency 32, IRQ 18
Memory at fe769000 (32-bit, non-prefetchable) [size=256]
Capabilities: [c0] Power Management version 2
Capabilities: [e4] Debug port: BAR=1 offset=00e0
Kernel driver in use: ehci-pci
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