From patchwork Tue Jan 2 21:45:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 13509480 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 1456E171A8; Tue, 2 Jan 2024 21:46:41 +0000 (UTC) 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="Gpb4tDkK" Received: from pps.filterd (m0279867.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 402Lgxn8002050; Tue, 2 Jan 2024 21:46:30 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=1gKa8uPfE60yWjTTUplQ LsTc6cS2VTs4IFAWikb6MkA=; b=Gpb4tDkK5J4yL5wJ4WysOFrZd/AJQqhL1DF7 Ma5cDWLe1yhAHqKmJJQP82kBXgaXoJEVJlWM8D5yASWHZUc3OhLvsE1bpniPukcO P7wVvCrbwMPukqyRT7vcAm9sHnzMURqkjzCPECzISUTsn9T/rW0tXCYWMLbg2SiL N3YOq1TiYdGLTIv7EFOSVbCe5ribfrN2/rA+Qe+gziPsrL9rJu6v5Y2AVdgptIzq /7w6oW5sBBNwhZP/opZKKv6OTGJA2R5mPB7Kj2hE5ZGM1Rp42dsGHfBMkv38ieqF gAiePOMLE2hcAbO1j9JMRy8g1xs1dWrnjhwVkUnA4gDLFWMe7g== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3vch7n96rk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 02 Jan 2024 21:46:30 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 402LkTPv009887 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 2 Jan 2024 21:46:29 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 15.2.1118.40; Tue, 2 Jan 2024 13:46:29 -0800 From: Wesley Cheng To: , , , , , , , , , , , , , , , CC: , , , , , , , Wesley Cheng Subject: [PATCH v12 39/41] ASoC: usb: Rediscover USB SND devices on USB port add Date: Tue, 2 Jan 2024 13:45:47 -0800 Message-ID: <20240102214549.22498-40-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20240102214549.22498-1-quic_wcheng@quicinc.com> References: <20240102214549.22498-1-quic_wcheng@quicinc.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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-GUID: DCvY8JT8db-7gXy2VOOFPQbWyYJQtg0T X-Proofpoint-ORIG-GUID: DCvY8JT8db-7gXy2VOOFPQbWyYJQtg0T X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_02,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 impostorscore=0 phishscore=0 mlxlogscore=999 mlxscore=0 lowpriorityscore=0 priorityscore=1501 malwarescore=0 bulkscore=0 spamscore=0 clxscore=1015 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2401020161 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 dfd6f53898c5..4d6d6ab0601f 100644 --- a/sound/soc/soc-usb.c +++ b/sound/soc/soc-usb.c @@ -437,6 +437,8 @@ int snd_soc_usb_add_port(struct snd_soc_usb *usb) list_add_tail(&usb->list, &usb_ctx_list); mutex_unlock(&ctx_mutex); + snd_usb_rediscover_devices(); + return 0; } EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);