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Subject[PATCH 3.16 202/305] usb: core: Fix hub port connection events lost
3.16.63-rc1 review patch.  If anyone has any objections, please let me know.


From: Dennis Wassenberg <>

commit 22454b79e6de05fa61a2a72d00d2eed798abbb75 upstream.

This will clear the USB_PORT_FEAT_C_CONNECTION bit in case of a hub port reset
only if a device is was attached to the hub port before resetting the hub port.

Using a Lenovo T480s attached to the ultra dock it was not possible to detect
some usb-c devices at the dock usb-c ports because the hub_port_reset code
will clear the USB_PORT_FEAT_C_CONNECTION bit after the actual hub port reset.
Using this device combo the USB_PORT_FEAT_C_CONNECTION bit was set between the
actual hub port reset and the clear of the USB_PORT_FEAT_C_CONNECTION bit.
This ends up with clearing the USB_PORT_FEAT_C_CONNECTION bit after the
new device was attached such that it was not detected.

This patch will not clear the USB_PORT_FEAT_C_CONNECTION bit if there is
currently no device attached to the port before the hub port reset.
This will avoid clearing the connection bit for new attached devices.

Signed-off-by: Dennis Wassenberg <>
Acked-by: Mathias Nyman <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Ben Hutchings <>
drivers/usb/core/hub.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2725,7 +2725,9 @@ static int hub_port_reset(struct usb_hub
usb_clear_port_feature(hub->hdev, port1,
- usb_clear_port_feature(hub->hdev, port1,
+ if (udev)
+ usb_clear_port_feature(hub->hdev, port1,

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