On Mon, 22 May 2017, Kai-Heng Feng wrote:

> So in order to detect SD card under runtime PM, it's a perfectly
> normal behavior, right?

Yes.

> Sorry for not explaining the original question well enough - the real
> problem is that after enabling runtime PM on EHCI, the two physical
> ports on the right side of the laptop no longer response to any
> device, e.g. an USB storage or an USB mouse.

Please collect two usbmon traces: one with runtime PM disabled and one
with runtime PM enabled.  For each trace, start with nothing plugged
into the right-side ports.  Then after the trace has been running for a
second or two, plug in a device.  Stop the trace a couple of seconds
after that.

Instructions for usbmon are in Documentation/usb/usbmon.txt in the 
kernel source.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to