On Wed, 24 May 2017, Kai-Heng Feng wrote: > 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 My mistake; we need to see the information from "lspci -vv -s 00:12.0" with two "v"'s, not just one. There's another piece of information you can collect. Mount a debugfs filesystem at /sys/kernel/debug, and then copy the contents of the file /sys/kernel/debug/usb/ehci/0000:00:12.0/registers Do this while the controller is still asleep (after the mouse is plugged in) and then again after it is awake. 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
