From patchwork Tue Aug 29 21:06:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 718558 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 68031CA0C0D for ; Tue, 29 Aug 2023 21:08:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239182AbjH2VIc (ORCPT ); Tue, 29 Aug 2023 17:08:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240651AbjH2VHj (ORCPT ); Tue, 29 Aug 2023 17:07:39 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DE95BD; Tue, 29 Aug 2023 14:07:36 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 37TCsbQ3005281; Tue, 29 Aug 2023 21:07:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=jt0oIgTyqjbTXFE8R+uBXHTwbnogDehsEUidVF5fLmc=; b=D6exVpbsp6DiENE2+cXYO0RMQQkv4BT7zgXBId/Eh8I5rwmpK9dM9yMirMmmy7fIB2iw +rGwND1cJqD2olUNCWCDNSy2JP7Cmse6YfeLwFlymYMXuJZ48ZytnEcuVOjVwkt8OZCq yhCO6oqFo1Gu/T45bjcHUdtYTGtzGPCSfY2IE2quhKXQ+Gf4LowDDWQgCbyOuY3Cm31w v900t7JzhjsFBCK6xwt2pyLeN/EwNc7G4Q9zRWou3NRfnyH9JfaElrf8E00ewgidQJbR g1ngVvChbqkrvzYrotikhTc6ZWE524HKcuw4MpZwIlPK2cdKUT8vcvZVhQwA/W0bMmqg +A== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ss2xbaxu8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 29 Aug 2023 21:07:18 +0000 Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 37TL7HCR014496 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 29 Aug 2023 21:07:17 GMT Received: from hu-wcheng-lv.qualcomm.com (10.49.16.6) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.36; Tue, 29 Aug 2023 14:07:16 -0700 From: Wesley Cheng To: , , , , , , , , , , , , CC: , , , , , , , Wesley Cheng Subject: [PATCH v5 32/32] sound: soc: soc-usb: Rediscover USB SND devices on USB port add Date: Tue, 29 Aug 2023 14:06:57 -0700 Message-ID: <20230829210657.9904-33-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230829210657.9904-1-quic_wcheng@quicinc.com> References: <20230829210657.9904-1-quic_wcheng@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01b.na.qualcomm.com (10.47.209.197) To nalasex01b.na.qualcomm.com (10.47.209.197) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: TYlLdWiodNg4W_7UoDVVyWgKiPuZB0ev X-Proofpoint-GUID: TYlLdWiodNg4W_7UoDVVyWgKiPuZB0ev X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-08-29_15,2023-08-29_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 suspectscore=0 mlxscore=0 clxscore=1015 impostorscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2308100000 definitions=main-2308290182 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In case the USB backend device has not been initialized/probed, USB SND device connections can still occur. When the USB backend is eventually made available, previous USB SND device connections are not communicated to the USB backend. Call snd_usb_rediscover_devices() to generate the connect callbacks for all USB SND devices connected. This will allow for the USB backend to be updated with the current set of devices available. The chip array entries are all populated and removed while under the register_mutex, so going over potential race conditions: Thread#1: q6usb_component_probe() --> snd_soc_usb_add_port() --> snd_usb_rediscover_devices() --> mutex_lock(register_mutex) Thread#2 --> usb_audio_disconnect() --> mutex_lock(register_mutex) So either thread#1 or thread#2 will complete first. If Thread#1 completes before thread#2: SOC USB will notify DPCM backend of the device connection. Shortly after, once thread#2 runs, we will get a disconnect event for the connected device. Thread#2 completes before thread#1: Then during snd_usb_rediscover_devices() it won't notify of any connection for that particular chip index. Signed-off-by: Wesley Cheng --- sound/soc/soc-usb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c index 619f9bfd6999..7df7f93cf5a2 100644 --- a/sound/soc/soc-usb.c +++ b/sound/soc/soc-usb.c @@ -115,6 +115,8 @@ struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv, list_add_tail(&usb->list, &usb_ctx_list); mutex_unlock(&ctx_mutex); + snd_usb_rediscover_devices(); + return usb; } EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);