Commit e92aee33 authored Oct 15, 2013 by Julius Werner Committed by Greg Kroah-Hartman Oct 16, 2013

usb: hub: Clear Port Reset Change during init/resume



This patch adds the Port Reset Change flag to the set of bits that are
preemptively cleared on init/resume of a hub. In theory this bit should
never be set unexpectedly... in practice it can still happen if BIOS,
SMM or ACPI code plays around with USB devices without cleaning up
correctly. This is especially dangerous for XHCI root hubs, which don't
generate any more Port Status Change Events until all change bits are
cleared, so this is a good precaution to have (similar to how it's
already done for the Warm Port Reset Change flag).

Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 06793f2d

drivers/usb/core/hub.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1135,6 +1135,11 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
		usb_clear_port_feature(hub->hdev, port1,
		USB_PORT_FEAT_C_ENABLE);
		}
		if (portchange & USB_PORT_STAT_C_RESET) {
		need_debounce_delay = true;
		usb_clear_port_feature(hub->hdev, port1,
		USB_PORT_FEAT_C_RESET);
		}
		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
		hub_is_superspeed(hub->hdev)) {
		need_debounce_delay = true;

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