From patchwork Fri May 5 14:36:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Konrad_Gr=C3=A4fe?= X-Patchwork-Id: 13232716 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8F40C7EE22 for ; Fri, 5 May 2023 14:37:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232699AbjEEOhL (ORCPT ); Fri, 5 May 2023 10:37:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231764AbjEEOhK (ORCPT ); Fri, 5 May 2023 10:37:10 -0400 Received: from www484.your-server.de (www484.your-server.de [78.47.237.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A81261991; Fri, 5 May 2023 07:37:08 -0700 (PDT) Received: from sslproxy06.your-server.de ([78.46.172.3]) by www484.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1puwYR-000CNI-NQ; Fri, 05 May 2023 16:37:04 +0200 Received: from [2003:ca:6730:e8f8:6bd1:e37b:34b5:f0b4] (helo=tethys.labor) by sslproxy06.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1puwYR-0004JI-H3; Fri, 05 May 2023 16:37:03 +0200 From: =?utf-8?q?Konrad_Gr=C3=A4fe?= To: Quentin Schulz , Greg Kroah-Hartman , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kyungmin Park , Andrzej Pietrasiewicz Cc: =?utf-8?q?Konrad_Gr=C3=A4fe?= , stable@vger.kernel.org Subject: [PATCH v5] usb: gadget: u_ether: Fix host MAC address case Date: Fri, 5 May 2023 16:36:40 +0200 Message-Id: <20230505143640.443014-1-k.graefe@gateware.de> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230427115120.241954-2-k.graefe@gateware.de> References: <20230427115120.241954-2-k.graefe@gateware.de> MIME-Version: 1.0 X-Authenticated-Sender: k.graefe@gateware.de X-Virus-Scanned: Clear (ClamAV 0.103.8/26897/Fri May 5 09:23:19 2023) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The CDC-ECM specification [1] requires to send the host MAC address as an uppercase hexadecimal string in chapter "5.4 Ethernet Networking Functional Descriptor": The Unicode character is chosen from the set of values 30h through 39h and 41h through 46h (0-9 and A-F). However, snprintf(.., "%pm", ..) generates a lowercase MAC address string. While most host drivers are tolerant to this, UsbNcm.sys on Windows 10 is not. Instead it uses a different MAC address with all bytes set to zero including and after the first byte containing a lowercase letter. On Windows 11 Microsoft fixed it, but apparently they did not backport the fix. This change fixes the issue by upper-casing the MAC to comply with the specification. [1]: https://www.usb.org/document-library/class-definitions-communication-devices-12, file ECM120.pdf Fixes: bcd4a1c40bee ("usb: gadget: u_ether: construct with default values and add setters/getters") Cc: stable@vger.kernel.org Signed-off-by: Konrad Gräfe --- Changes since v4: * Use string_upper() instead of a special format string Changes since v3: None Changes since v2: * Add uppercase MAC address format string and use that instead of manually uppercasing the resulting MAC address string. Changes since v1: * Fixed checkpatch.pl warnings drivers/usb/gadget/function/u_ether.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 6956ad8ba8dd..a366abb45623 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include "u_ether.h" @@ -965,6 +966,8 @@ int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len) dev = netdev_priv(net); snprintf(host_addr, len, "%pm", dev->host_mac); + string_upper(host_addr, host_addr); + return strlen(host_addr); } EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);