From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932420Ab2L1TTj (ORCPT ); Fri, 28 Dec 2012 14:19:39 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55585 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932396Ab2L1TTc (ORCPT ); Fri, 28 Dec 2012 14:19:32 -0500 Message-Id: <20121228190340.573255522@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:04:20 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alan Stern , Sarah Sharp , Greg Kroah-Hartman Subject: [ 050/173] USB: fix endpoint-disabling for failed config changes In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit 36caff5d795429c572443894e8789c2150dd796b upstream. This patch (as1631) fixes a bug that shows up when a config change fails for a device under an xHCI controller. The controller needs to be told to disable the endpoints that have been enabled for the new config. The existing code does this, but before storing the information about which endpoints were enabled! As a result, any second attempt to install the new config is doomed to fail because xhci-hcd will refuse to enable an endpoint that is already enabled. The patch optimistically initializes the new endpoints' device structures before asking the device to switch to the new config. If the request fails then the endpoint information is already stored, so we can use usb_hcd_alloc_bandwidth() to disable the endpoints with no trouble. The rest of the error path is slightly more complex now; we have to disable the new interfaces and call put_device() rather than simply deallocating them. Signed-off-by: Alan Stern Reported-and-tested-by: Matthias Schniedermeyer CC: Sarah Sharp Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/core/message.c | 54 +++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 23 deletions(-) --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1770,28 +1770,8 @@ free_interfaces: goto free_interfaces; } - ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), - USB_REQ_SET_CONFIGURATION, 0, configuration, 0, - NULL, 0, USB_CTRL_SET_TIMEOUT); - if (ret < 0) { - /* All the old state is gone, so what else can we do? - * The device is probably useless now anyway. - */ - cp = NULL; - } - - dev->actconfig = cp; - if (!cp) { - usb_set_device_state(dev, USB_STATE_ADDRESS); - usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); - mutex_unlock(hcd->bandwidth_mutex); - usb_autosuspend_device(dev); - goto free_interfaces; - } - mutex_unlock(hcd->bandwidth_mutex); - usb_set_device_state(dev, USB_STATE_CONFIGURED); - - /* Initialize the new interface structures and the + /* + * Initialize the new interface structures and the * hc/hcd/usbcore interface/endpoint state. */ for (i = 0; i < nintf; ++i) { @@ -1835,6 +1815,35 @@ free_interfaces: } kfree(new_interfaces); + ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), + USB_REQ_SET_CONFIGURATION, 0, configuration, 0, + NULL, 0, USB_CTRL_SET_TIMEOUT); + if (ret < 0 && cp) { + /* + * All the old state is gone, so what else can we do? + * The device is probably useless now anyway. + */ + usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); + for (i = 0; i < nintf; ++i) { + usb_disable_interface(dev, cp->interface[i], true); + put_device(&cp->interface[i]->dev); + cp->interface[i] = NULL; + } + cp = NULL; + } + + dev->actconfig = cp; + mutex_unlock(hcd->bandwidth_mutex); + + if (!cp) { + usb_set_device_state(dev, USB_STATE_ADDRESS); + + /* Leave LPM disabled while the device is unconfigured. */ + usb_autosuspend_device(dev); + return ret; + } + usb_set_device_state(dev, USB_STATE_CONFIGURED); + if (cp->string == NULL && !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS)) cp->string = usb_cache_string(dev, cp->desc.iConfiguration);