On Thu, Dec 26, 2019 at 02:46:15PM -0500, Alan Stern wrote:
On Thu, 26 Dec 2019, Guenter Roeck wrote:
On shutdown, ehci_power_off() is called unconditionally to power off each port, even if it was never called to power on the port. For chipidea, this results in a call to ehci_ci_portpower() with a request to power off ports even if the port was never powered on. This results in the following warning from the regulator code.
That's weird -- we should always power-on every port during hub initialization.
That is what I would have assumed, but test code shows that it doesn't happen.
It looks like there's a bug in hub.c:hub_activate(): The line under HUB_INIT which calls hub_power_on() should call usb_hub_set_port_power() instead. In fact, the comment near the start
usb_hub_set_port_power() operates on a port of the hub. hub_activate() operates on the hub itself, or at least I think it does. I don't know how to convert the calls. Also, there are more calls to hub_power_on() in the same function. Can you provide more details on what to do, or even better a patch for me to test ?
Thanks, Guenter
of hub_power_on() is wrong. It says "Enable power on each port", but in fact it only enables power for ports that had been powered-on previously (i.e., the port's bit in hub->power_bits was set). Apparently this got messed up in commit ad493e5e5805 ("usb: add usb port auto power off mechanism").
Now, the chipidea driver may still need to be updated, because ehci_turn_off_all_ports() will still be called during shutdown and it will try to power-down all ports, even those which are already powered down (for example, because the port is suspended).
Alan Stern