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usb: core: Fix hub port connection events lost

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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 <dennis.wassenberg@secunet.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dennis Wassenberg 2018-11-13 14:40:34 +01:00 committed by Greg Kroah-Hartman
parent 4b8440abc9
commit 22454b79e6
1 changed files with 3 additions and 1 deletions
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4
drivers/usb/core/hub.c
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@ -2850,7 +2850,9 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
USB_PORT_FEAT_C_BH_PORT_RESET);
usb_clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_PORT_LINK_STATE);
usb_clear_port_feature(hub->hdev, port1,
if (udev)
usb_clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_CONNECTION);
/*