From nobody Fri Nov 29 05:37:41 2024 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 5DF56157469; Wed, 25 Sep 2024 01:01:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727226084; cv=none; b=TkWadC7bC1vD5t2E825/3R924n6BKRsmjYCoKcR+e6bi/jJqFDxALEJmmS+IdWfZKnxTl7Ex31ogTSVWCfwDDYHihj67LJRFBy0NGKHIHLbynVd1BlnMdSS7BMlZd9OPRLu1Nw8k5lku7LmxTKEwojhcPCpr3zOCOk2nWXUpBVc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727226084; c=relaxed/simple; bh=prnyaP8xdPvgf7lPSdgoOnTFSQEEfdLilloaJUXm1RE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kl5rjkOEDANeZGK0kS0a/pcoC4zsnFan+QyH7OjC7kHworObx8AEfPfHJzHwQPsPNY2RyUwsXJjh9+2NQpDHfhIpi5kOG6MPxdPK9zBhgzTe7J1EGpjU4Wx19Z3ohhxMzHh3nSr6ZyPO32gCyyExhUWheBYNIhK5DXdw3VX1w7A= 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=pjldD4f9; arc=none smtp.client-ip=205.220.180.131 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="pjldD4f9" Received: from pps.filterd (m0279871.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 48OIJGAj001625; Wed, 25 Sep 2024 01:00:22 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= IHuzCQGYpXyTPH0RihFbQD623zcQRcB8CUdC3cqWdMA=; b=pjldD4f9IXUoQo+6 v0DhTrFEJMo29LhW+GBGrrCDkdYe00bE7NcqwI+9FiM4djrz0OYEDpDczfE8hVOS 3C4ivw4yDwn+gJEkjIdkLy9uf0kfmgkki+u+Q8lGxIs346X47HAtcOYfwHf6tlii nKkIuAjL9QutcCbd6MiS8pNOBegMxhWwd3107CTRhcnMeL7GXmsi1EwgCvzGSqFL pJODt2TPVDdE4uDtOhKtyhRE+WF1b/32DaW0U275vhBMnKZVfTvwlRmnMyJ4sPut MKHLvDF1hPGGlDdjZ7xTIhQeGkAoIoZft1FFbAoD6XVdMhTnvz8CtXkNMpsfYD/+ XpGafg== Received: from nalasppmta03.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 41snqyjg40-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 25 Sep 2024 01:00:21 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA03.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 48P10Kac022123 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 25 Sep 2024 01:00:20 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; Tue, 24 Sep 2024 18:00:20 -0700 From: Wesley Cheng To: , , , , , , , , , , , , , , CC: , , , , , , , , Wesley Cheng Subject: [PATCH v28 32/32] ASoC: usb: Rediscover USB SND devices on USB port add Date: Tue, 24 Sep 2024 18:00:00 -0700 Message-ID: <20240925010000.2231406-33-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240925010000.2231406-1-quic_wcheng@quicinc.com> References: <20240925010000.2231406-1-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-GUID: vKi0Sn_XlvQ3aFwyj_s_nRXk2lodc4I0 X-Proofpoint-ORIG-GUID: vKi0Sn_XlvQ3aFwyj_s_nRXk2lodc4I0 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 priorityscore=1501 impostorscore=0 adultscore=0 bulkscore=0 phishscore=0 mlxlogscore=999 spamscore=0 lowpriorityscore=0 clxscore=1015 mlxscore=0 malwarescore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2408220000 definitions=main-2409250005 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);