From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Julius Werner" , "Greg Kroah-Hartman" , "Alan Stern" Date: Sun, 29 Dec 2013 03:08:43 +0100 Message-ID: Subject: [PATCH 3.2 005/185] usb: hub: Clear Port Reset Change during init/resume In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Julius Werner commit e92aee330837e4911553761490a8fb843f2053a6 upstream. 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 Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: - Adjust context - s/usb_clear_port_feature/clear_port_feature/] Signed-off-by: Ben Hutchings --- drivers/usb/core/hub.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -900,6 +900,11 @@ static void hub_activate(struct usb_hub clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_PORT_LINK_STATE); } + if (portchange & USB_PORT_STAT_C_RESET) { + need_debounce_delay = true; + clear_port_feature(hub->hdev, port1, + USB_PORT_FEAT_C_RESET); + } if ((portchange & USB_PORT_STAT_C_BH_RESET) && hub_is_superspeed(hub->hdev)) {