From patchwork Fri Jan 18 14:25:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Bj=C3=B8rn_Mork?= X-Patchwork-Id: 213617 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id CA5332C0079 for ; Sat, 19 Jan 2013 01:26:16 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756001Ab3ARO0M (ORCPT ); Fri, 18 Jan 2013 09:26:12 -0500 Received: from canardo.mork.no ([148.122.252.1]:44743 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755595Ab3ARO0J (ORCPT ); Fri, 18 Jan 2013 09:26:09 -0500 Received: from nemi.mork.no (ip6-localhost [IPv6:::1]) by canardo.mork.no (8.14.3/8.14.3) with ESMTP id r0IEPskR013870 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Fri, 18 Jan 2013 15:25:54 +0100 Received: from bjorn by nemi.mork.no with local (Exim 4.80) (envelope-from ) id 1TwCtG-0002cz-7a; Fri, 18 Jan 2013 15:25:54 +0100 From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= To: netdev@vger.kernel.org Cc: linux-usb@vger.kernel.org, =?UTF-8?q?Bj=C3=B8rn=20Mork?= , Greg Suarez , Alexey Orishko Subject: [PATCH net] net: cdc_ncm: workaround for missing CDC Union Date: Fri, 18 Jan 2013 15:25:47 +0100 Message-Id: <1358519147-10073-1-git-send-email-bjorn@mork.no> X-Mailer: git-send-email 1.7.10.4 MIME-Version: 1.0 X-Spam-Status: No, score=-2.5 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on canardo.mork.no X-Virus-Scanned: clamav-milter 0.97.6 at canardo X-Virus-Status: Clean Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Adding support for the MBIM mode in some Sierra Wireless devices. Some Sierra Wireless firmwares support CDC MBIM but have no CDC Union funtional descriptor. This violates the MBIM specification, but we can easily work around the bug by looking at the Interface Association Descriptor instead. This is most likely what Windows uses too, which explains how the firmware bug has gone unnoticed until now. This change will not affect any currently supported device conforming to the NCM or MBIM specifications, as they must have the CDC Union descriptor. Cc: Greg Suarez Cc: Alexey Orishko Signed-off-by: Bjørn Mork --- drivers/net/usb/cdc_ncm.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 71b6e92..5c1210f 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -344,6 +344,21 @@ static const struct ethtool_ops cdc_ncm_ethtool_ops = { .nway_reset = usbnet_nway_reset, }; +/* return first slave interface if an IAD matches the given master */ +static struct usb_interface *get_iad_slave(struct usb_device *udev, + struct usb_interface *master) { + int i; + struct usb_interface_assoc_descriptor *iad; + u8 mnum = master->cur_altsetting->desc.bInterfaceNumber; + + for (i = 0; i < USB_MAXIADS; i++) { + iad = udev->actconfig->intf_assoc[i]; + if (iad->bFirstInterface == mnum && iad->bInterfaceCount == 2) + return usb_ifnum_to_if(udev, mnum + 1); + } + return NULL; +} + int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting) { struct cdc_ncm_ctx *ctx; @@ -435,6 +450,16 @@ advance: len -= temp; } + /* some buggy devices have an IAD but no CDC Union */ + if (!ctx->union_desc) { + dev_dbg(&intf->dev, "missing CDC Union descriptor\n"); + ctx->data = get_iad_slave(dev->udev, intf); + if (ctx->data) { + ctx->control = intf; + dev_dbg(&intf->dev, "got slave from IAD\n"); + } + } + /* check if we got everything */ if ((ctx->control == NULL) || (ctx->data == NULL) || ((!ctx->mbim_desc) && ((ctx->ether_desc == NULL) || (ctx->control != intf))))