This is a note to let you know that I've just added the patch titled

usb: hub: Cycle HUB power when initialization fails

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: usb-hub-cycle-hub-power-when-initialization-fails.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 973593a960ddac0f14f0d8877d2d0abe0afda795 Mon Sep 17 00:00:00 2001

From: Mike Looijmans mike.looijmans@topic.nl Date: Thu, 9 Nov 2017 13:16:46 +0100 Subject: usb: hub: Cycle HUB power when initialization fails

From: Mike Looijmans mike.looijmans@topic.nl

commit 973593a960ddac0f14f0d8877d2d0abe0afda795 upstream.

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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/usb/core/hub.c | 9 +++++++++ 1 file changed, 9 insertions(+)

--- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4816,6 +4816,15 @@ 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 ||

Patches currently in stable-queue which might be from mike.looijmans@topic.nl are

queue-3.18/usb-hub-cycle-hub-power-when-initialization-fails.patch