On 02.10.2018 16:06, Jan Kara wrote:
Hello,
my wife has HP 255 G6 laptop. When it is attached to AC, everything works
as expected however when it is running on battery, USB hotplug stops
working - newly plugged devices do not appear to be visible to the kernel.
Only when the AC is plugged back in, the kernel suddently wakes up and
detects all newly attached devices. Maybe it is related to some power
management? Any idea how to debug this? Dmesg from the system is attached.
The kernels I've tested with (both behave the same way) are 4.18.11 kernel
and also openSUSE Leap 15 kernel which is 4.12-based. Thanks in advance for
any help.
Are you running laptop mode tools or similar that would enable runtime suspend
D3 state for xhci controller?
what does lspci -vv say?
check the content of the following files while running on battery:
cat /sys/bus/pci/devices/0000:00:10.0/firmware_node/power_state
cat /sys/bus/pci/devices/0000:00:10.0/power/control
try: echo on > /sys/bus/pci/devices/0000:00:10.0/power/control
before pluggin in a usb device, does it help?
cat /proc/acpi/wakeup content could be useful
Also full dmesg including first plugging in the usb device, and then the AC
power.
It will show if the connected devices are USB2 or USB3 devices, and if they are
connected
to EHCI of xHC controller?
Thanks
Mathias
