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 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-hub-cycle-hub-power-when-initialization-fails.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 973593a960ddac0f14f0d8877d2d0abe0afda795 Mon Sep 17 00:00:00 2001
From: Mike Looijmans <mike.looijmans@xxxxxxxx>
Date: Thu, 9 Nov 2017 13:16:46 +0100
Subject: usb: hub: Cycle HUB power when initialization fails
From: Mike Looijmans <mike.looijmans@xxxxxxxx>
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@xxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4925,6 +4925,15 @@ 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@xxxxxxxx are
queue-4.9/i2c-i2c-cadence-initialize-configuration-before-probing-devices.patch
queue-4.9/usb-hub-cycle-hub-power-when-initialization-fails.patch