From e92aee330837e4911553761490a8fb843f2053a6 Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Tue, 15 Oct 2013 17:45:00 -0700 Subject: [PATCH] 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 Acked-by: Alan Stern Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 3f8933f10e7d..92dde941fdbe 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -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; -- 2.20.1