From nobody Wed Nov 27 11:53:27 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 76ACF1D0DCB; Fri, 11 Oct 2024 00:07:42 +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=1728605267; cv=none; b=IKsFNVDjCtzKJ3xESTT5XS36a4P36AW8Q4sD/M+Dzld/43viMoqUjtDeJEAEf7kc7OzhezHLY4XDKBPa/Sb9sLL/RDNUHV+Bq+GH++4qC12kcQLAdXf0+/JRNIBRS8+DU1smwqo90sCBYd6EDR4+GX5JyNAUfJGxesFihG7sff8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728605267; c=relaxed/simple; bh=prnyaP8xdPvgf7lPSdgoOnTFSQEEfdLilloaJUXm1RE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tu6QWL1pu1N3kPFm1tzalRjbctcK0hiGSWEYRTYsWqqiYwOPApBXYb791XNtzyhwjcn4z2h1r9AUV9Qn/C9K/qaBI3yslxoxkv0saegQaGjf4EwmXOUtAAK7Rk880vtbRjB/5/KBBDSJ+BSyi12iXGDiDVxIdB6k9SmbCVgyT24= 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=ogz7h0uI; 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="ogz7h0uI" Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49AF5mkH027240; 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= IHuzCQGYpXyTPH0RihFbQD623zcQRcB8CUdC3cqWdMA=; b=ogz7h0uIHzNX7xfS BO/MpN4he3m3wqw60PypYF2GPTFFd2g59CsYkvqsecSdw+zKDZWJ6Xaa9K/u3y0w IbiSd4gvPdyMKKjnUFw7N9a161pg3/XZ1jDNciLEOFs3cGamFXy0ErWcdE0oqJtd kbi9CH8GUVW7zwPWmMMxjG8/LTa+TrBwatZKemFEbmz0R/zmjhkKI6tkNmtELpqV gjzW8t/Oo8Uv7DUNF7ZXp7Sa3ojOKqZAYdUYBHNw3Vbn4jIYTMZVb8WGJdjB1aGJ tk5NCKgpryvLQVSOq31J1M7kc1s6u+W6LvR7XhPzCnhfu8XIqv6aWu5yGiXFyEYS 9MK6CA== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 424cy7mk02-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Oct 2024 00:07:22 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA04.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 49B07Kaq003489 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Oct 2024 00:07:20 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; Thu, 10 Oct 2024 17:07:20 -0700 From: Wesley Cheng To: , , , , , , , , , , , , , , CC: , , , , , , , , Wesley Cheng Subject: [PATCH v28 32/32] ASoC: usb: Rediscover USB SND devices on USB port add Date: Thu, 10 Oct 2024 17:06:49 -0700 Message-ID: <20241011000650.2585600-65-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: AAPjahDdlI_c_uTYNrqc5r3nTXa0PK1F X-Proofpoint-GUID: AAPjahDdlI_c_uTYNrqc5r3nTXa0PK1F 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 phishscore=0 impostorscore=0 adultscore=0 mlxscore=0 lowpriorityscore=0 suspectscore=0 spamscore=0 priorityscore=1501 clxscore=1015 bulkscore=0 malwarescore=0 mlxlogscore=999 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 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);