From patchwork Tue Sep 11 18:06:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saranya Gopal X-Patchwork-Id: 10596131 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C718514F9 for ; Tue, 11 Sep 2018 18:12:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC65A29C03 for ; Tue, 11 Sep 2018 18:12:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A0E7F29C0E; Tue, 11 Sep 2018 18:12:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2543D29C03 for ; Tue, 11 Sep 2018 18:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727673AbeIKXMo (ORCPT ); Tue, 11 Sep 2018 19:12:44 -0400 Received: from mga03.intel.com ([134.134.136.65]:51969 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726622AbeIKXMo (ORCPT ); Tue, 11 Sep 2018 19:12:44 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2018 11:12:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,361,1531810800"; d="scan'208";a="70061658" Received: from saranya-h97m-d3h.iind.intel.com ([10.66.254.75]) by fmsmga008.fm.intel.com with ESMTP; 11 Sep 2018 11:12:13 -0700 From: saranya.gopal@intel.com To: linux-usb@vger.kernel.org Cc: felipe.balbi@linux.intel.com, rajaram.regupathy@intel.com, abhilash.k.v@intel.com, m.balaji@intel.com, Saranya Gopal Subject: [PATCH] usbcore: Select UAC3 configuration for audio if present Date: Tue, 11 Sep 2018 23:36:30 +0530 Message-Id: <1536689190-24989-1-git-send-email-saranya.gopal@intel.com> X-Mailer: git-send-email 1.9.1 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Saranya Gopal USB audio class 3.0 specification introduced many significant changes like - new power domains, support for LPM/L1 - new cluster descriptor - new high capability and class-specific string descriptors - BADD profiles - ... and many other things (check spec from link below: http://www.usb.org/developers/docs/devclass_docs/USB_Audio_v3.0.zip) Now that UAC3 is supported in linux, choose UAC3 configuration for audio if the device supports it. Selecting this configuration will enable the system to save power by leveraging the new power domains and LPM L1 capability and also support new codec types and data formats for consumer audio applications. Signed-off-by: Saranya Gopal Reviewed-by: Felipe Balbi --- drivers/usb/core/generic.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index bc8242b..dc6eb24 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -21,6 +21,7 @@ #include #include +#include #include "usb.h" static inline const char *plural(int n) @@ -42,6 +43,16 @@ static int is_activesync(struct usb_interface_descriptor *desc) && desc->bInterfaceProtocol == 1; } +static int is_audio(struct usb_interface_descriptor *desc) +{ + return desc->bInterfaceClass == USB_CLASS_AUDIO; +} + +static int is_uac3_config(struct usb_interface_descriptor *desc) +{ + return desc->bInterfaceProtocol == UAC_VERSION_3; +} + int usb_choose_configuration(struct usb_device *udev) { int i; @@ -121,6 +132,23 @@ int usb_choose_configuration(struct usb_device *udev) #endif } + /* + * Select first configuration as default for audio so that + * devices that don't comply with UAC3 protocol are supported. + * But, still iterate through other configurations and + * select UAC3 compliant config if present. + */ + if (i == 0 && num_configs > 1 && desc && is_audio(desc)) { + best = c; + continue; + } + + if (i > 0 && desc && is_audio(desc)) { + if (is_uac3_config(desc)) + best = c; + break; + } + /* From the remaining configs, choose the first one whose * first interface is for a non-vendor-specific class. * Reason: Linux is more likely to have a class driver