From nobody Wed Nov 27 12:23:49 2024 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F1961EBA0D; Fri, 11 Oct 2024 00:07:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728605271; cv=none; b=ZPF0yJyP5aBXRXkYyZDhzdeVxh5yZLc4fpFjSVqUgRcsOv/rFMTJuAVCiMuXMJ9+5wxkY88QktOI5VXPAIzci/IlqOkOn3c9rMLM34JrkVfmQnzzFi2ZJjYJWmemubvkhqRk60Mfp9npRnCwK7OnoEa7f4cG8CKyumG2o6/RnD0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728605271; c=relaxed/simple; bh=qU0dUNxFUuN/ND2hfWc0/b53f/OYr4+0HIcF9EoyLxI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gy9NRoz+tp9t6ZdyCvIw2Vcvp/esew+cHVVmAalXaa7KJ+ZXK5ki7q89CY670Utf5NJLjEoMPlvyKiHbWXSs16wyNJ+kSAACIuudf5xnR1+6NlxUIcPeYoPiHUr8S+BFlVPl2uDAxwXtAhJYK8E8ByU5IASUF0gKI4TYu3DZi8Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=G69tp7ac; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="G69tp7ac" Received: from pps.filterd (m0279863.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49ACiZVu009190; Fri, 11 Oct 2024 00:07:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= M4IGsOidRHFIubeJL9OdlEYfFZx1GNBQBMy1HdndUaw=; b=G69tp7ac8hXPF2wN i+BWaqvrNw6N4F0Zwb4rH2jbMvCpl1i9qB45EJTaL87S5cNWvWHElVwbnKcGPHUA TGI6ixYDvtwevNEHjYN8zZNeMDedFjJXZnIBRj8Ur7NGp03JDTuV4hJxjXKU6d7h 3AM1Ah+6fcGyGZLG0EM7QM5vvAFTEnFFOyuoMwv/W0zgRGThkElMrwhRE284M9yM 6eDIsUrmMU2g3O+MK2SjfEiVW2eqvbOS/PsSI+IJrmG2GvQebvzp72CDnUznseyK 9OxK2Tyw8YbEyKYsrDfDatNn3NTtApm8frQZhLkirENKuf6sKCxbhmdKEaCPcQha y7VPBw== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 425tn150wm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Oct 2024 00:07:21 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA02.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 49B07LuM016447 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Oct 2024 00:07:21 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 15.2.1544.9; Thu, 10 Oct 2024 17:07:20 -0700 From: Wesley Cheng To: , , , , , , , , , , , , , , CC: , , , , , , , , Wesley Cheng Subject: [PATCH v28 33/33] ASoC: usb: Rediscover USB SND devices on USB port add Date: Thu, 10 Oct 2024 17:06:50 -0700 Message-ID: <20241011000650.2585600-66-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241011000650.2585600-1-quic_wcheng@quicinc.com> References: <20241011000650.2585600-1-quic_wcheng@quicinc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: jJig91f6tQbqCiu6QF3XWFmGK0ex3QE0 X-Proofpoint-GUID: jJig91f6tQbqCiu6QF3XWFmGK0ex3QE0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 bulkscore=0 suspectscore=0 priorityscore=1501 mlxlogscore=999 impostorscore=0 spamscore=0 lowpriorityscore=0 phishscore=0 clxscore=1015 malwarescore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410100159 Content-Type: text/plain; charset="utf-8" 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 e56826f1df71..ee566ca7c675 100644 --- a/sound/soc/soc-usb.c +++ b/sound/soc/soc-usb.c @@ -279,6 +279,8 @@ void snd_soc_usb_add_port(struct snd_soc_usb *usb) mutex_lock(&ctx_mutex); list_add_tail(&usb->list, &usb_ctx_list); mutex_unlock(&ctx_mutex); + + snd_usb_rediscover_devices(); } EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);