From nobody Tue Nov 12 22:34:20 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 9940C1C0DF0; Thu, 12 Sep 2024 19:40:24 +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=1726170026; cv=none; b=NuAB80l2OTPk2wuaLZUrRfbzQjdZPAswJNi/Hqx1F+pf0YV1YOUJ75tyKntuKx+xQ/UbnbBoyZqnzHMQ3dth2ak7HDTzBkWgBHNsGA2G9rn55xhxksuvStoH/TPK+Knj7n4DZXKB4O6UttcuCaUbAQvaVRon02/J2AIUkYxV/TM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726170026; c=relaxed/simple; bh=prnyaP8xdPvgf7lPSdgoOnTFSQEEfdLilloaJUXm1RE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=d8H3J7DM9tfjMjm8R9XjYGaX0C9ZODgPS9zhYkkYFfCqpAcmuK97ecHJFqh2M3PBexj27HnT1eq9nzWqEBVJUo4rVa4RlqIKi3xMKS89stsy63wn0q7ZV5Xk6hWi2ixidU6Be1PNLthJIjeOCdZG2+RIopLKJ7CUv+qxCf4cil0= 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=R3pxgM5d; 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="R3pxgM5d" Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 48CHtE53009379; Thu, 12 Sep 2024 19:39:57 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= IHuzCQGYpXyTPH0RihFbQD623zcQRcB8CUdC3cqWdMA=; b=R3pxgM5dNh9T2Az8 PZ5ac24L2Q8WQ/2fKUD/e/lochroPqS9LGXSO1VmS1fyup/qE+XRUPYUt4seyEum P82YhN689vuOSeFV3Er0e1JvIoh8/cSEmjeDUHztrw2sJyqVv2i22TC/wqS6sBZf W1d+vrhDiD4du2Idr2ppYi4i3MMLWEiivJu9VMcGcYSvw+pBtYQBVUqEfxoovTkJ XYfRRLZayzK8+6wHQTr9IvC7cKepQSmbrR6pMhnJnBwnTWP1NSlZ+nE19fjAvj+t NzO8OeZfTtbu9v/bB4gnZQ9r+g9pq7RGzXqXKHWmcbCFDXxFT0Brsh1fsU6sV9as IrPD/Q== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 41gy6peeyj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 12 Sep 2024 19:39:56 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA01.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 48CJdubu006060 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 12 Sep 2024 19:39:56 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, 12 Sep 2024 12:39:55 -0700 From: Wesley Cheng To: , , , , , , , , , , , , , , CC: , , , , , , , , Wesley Cheng Subject: [PATCH v27 32/32] ASoC: usb: Rediscover USB SND devices on USB port add Date: Thu, 12 Sep 2024 12:39:35 -0700 Message-ID: <20240912193935.1916426-33-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240912193935.1916426-1-quic_wcheng@quicinc.com> References: <20240912193935.1916426-1-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: nalasex01c.na.qualcomm.com (10.47.97.35) 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: ogiyPitW642ue2kmpSl3oPFemrvuiZ_P X-Proofpoint-GUID: ogiyPitW642ue2kmpSl3oPFemrvuiZ_P 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 clxscore=1015 adultscore=0 bulkscore=0 lowpriorityscore=0 mlxlogscore=999 spamscore=0 phishscore=0 impostorscore=0 suspectscore=0 mlxscore=0 malwarescore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2408220000 definitions=main-2409120144 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 f88ccf90df32..3457bb51a0a1 100644 --- a/sound/soc/soc-usb.c +++ b/sound/soc/soc-usb.c @@ -252,6 +252,8 @@ 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);