Commit 973593a9 authored Nov 09, 2017 by Mike Looijmans Committed by Greg Kroah-Hartman Nov 28, 2017

usb: hub: Cycle HUB power when initialization fails



Sometimes the USB device gets confused about the state of the initialization and
the connection fails. In particular, the device thinks that it's already set up
and running while the host thinks the device still needs to be configured. To
work around this issue, power-cycle the hub's output to issue a sort of "reset"
to the device. This makes the device restart its state machine and then the
initialization succeeds.

This fixes problems where the kernel reports a list of errors like this:

usb 1-1.3: device not accepting address 19, error -71

The end result is a non-functioning device. After this patch, the sequence
becomes like this:

usb 1-1.3: new high-speed USB device number 18 using ci_hdrc
usb 1-1.3: device not accepting address 18, error -71
usb 1-1.3: new high-speed USB device number 19 using ci_hdrc
usb 1-1.3: device not accepting address 19, error -71
usb 1-1-port3: attempt power cycle
usb 1-1.3: new high-speed USB device number 21 using ci_hdrc
usb-storage 1-1.3:1.2: USB Mass Storage device detected

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 81cf4a45

drivers/usb/core/hub.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -4948,6 +4948,15 @@ loop:
		usb_put_dev(udev);
		if ((status == -ENOTCONN) \|\| (status == -ENOTSUPP))
		break;

		/* When halfway through our retry count, power-cycle the port */
		if (i == (SET_CONFIG_TRIES / 2) - 1) {
		dev_info(&port_dev->dev, "attempt power cycle\n");
		usb_hub_set_port_power(hdev, hub, port1, false);
		msleep(2 * hub_power_on_good_delay(hub));
		usb_hub_set_port_power(hdev, hub, port1, true);
		msleep(hub_power_on_good_delay(hub));
		}
		}
		if (hub->hdev->parent \|\|
		!hcd->driver->port_handed_over \|\|

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