From mboxrd@z Thu Jan 1 00:00:00 1970 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 B26A638E8A4 for ; Mon, 1 Jun 2026 23:43:59 +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=1780357440; cv=none; b=kKvd8LYinCBQXG/gx0fGrzJPKC8pb59CyPZUK7M0/gmOFp+cCKwG0khOVM2ezgWRPS8C0TVAcN7HHUTnnOKkV0DtGd31s8cXnNSjRyBqwpwZZKBaESvP9r6iRpYVZ76kUOQsKdrqgZhzJ9ssUyeSrIY+L7fraPNq+aW4CKwPHtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780357440; c=relaxed/simple; bh=bRMIe/SgZcXtejTqCmwYq4zJAtnC8yYbh841gtrQP8E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=td0Oc0BY4aHoPzPfF2EdHYQrvaWEeQK7e7Ls9cKkAfwaNYwPrKEXCwpbVaGpZtdiDEfaf/fNBigsZowPQiYptCRShFIeNeuiEvOCK1Vw0cjBrZZfAwY3rWCp4Fj8/oEF7buJYdDq9vh0qoA3L57MdOAVCwGavp5Gg+sZkbxY4ic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=ByPfXpJ2; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=OWDBlkVD; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="ByPfXpJ2"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="OWDBlkVD" Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 651HMrw1334628 for ; Mon, 1 Jun 2026 23:43:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= LVWwkZdU+/i7RbvWnqhsoX5gtYbQkKJMH7YMGSl1o4g=; b=ByPfXpJ2uLyF5443 mPQ07Yn0A9unlBgTmGU6fqGtoypofvPXpflMfxH/m2wffKDrTXh318IWB2hbrfTk Rm0TJvkT8tA3iL4Lzv8M653RS0Y8+V7W9wF/xaNzpdQk0GoUBUfKpmoZcs3SBQUn RzYPGOcPiUSUiT7l7Sc0uiWL5FN3l1hYvLwodbYBSGUBbGJGyphnjputMQfxH/tS CvWUmCPKcoidcazjP5ewbuMJI5TN5fjzDAT9VbaBUKxo2yxsL+Ojd4fx9Lqt3h1Y oxVh3zfS17TSJo1+qzD+k4UyU1RCtnJ7GJhRLG86b7nHaXmprxnzsDnLC6LrWeIu SHKFAQ== Received: from mail-dy1-f197.google.com (mail-dy1-f197.google.com [74.125.82.197]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4eh8tfu4gt-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Mon, 01 Jun 2026 23:43:58 +0000 (GMT) Received: by mail-dy1-f197.google.com with SMTP id 5a478bee46e88-304ed777a96so2076673eec.1 for ; Mon, 01 Jun 2026 16:43:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1780357438; x=1780962238; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=LVWwkZdU+/i7RbvWnqhsoX5gtYbQkKJMH7YMGSl1o4g=; b=OWDBlkVDnKhCXRh1yv8mvsahj13c+38cJVJZ6O+uk+qER25Vtzj6RU7YsbHkDW//h1 c63Dl06jF2zx9AABYafpn1tgEEE21Sd9B5updsozcBzGGll0AUQnpjfYKms/NLMt1PXy KmEoCYPGuKkrirBYWoOlNlxQwl1NOANllou+Y5i+8t/CulQAs/DytVTFD4iCkMwYx0+/ RsDjas9luo8Ces3ujqFclRykf/eUksqTF9E6+sIAG13T7W+2Ujkb2g8rJKv0X/YQ9fnr AnQncMRMI1vicjaNG8AcO1gYBsLQrt1J2zuieGPxDHzXr/Wxy7cCUbEVZtvZTHHy/OFW 9i6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780357438; x=1780962238; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=LVWwkZdU+/i7RbvWnqhsoX5gtYbQkKJMH7YMGSl1o4g=; b=UX+6kSS402OF2aagqcNxzcZP3Zn7OPMsYYZ955JgrPUK751gsZkyzx1cku/rVWSNew +JkrPOtvL/x6SgMFuuX+WbK8Ic25haHx+U5392DdD+yUyotNmvXcxlQoFUG4PQGaX7oh gVIePfRnyq9ZiQz08XuGP0kYH7Chra4CXy+7tt4mztq1mi9RLvhGA4uKsH3TIzB7NaU0 tJ+Sqbz8CiubafjMBywAJVVSgvElzse/qC/1d1cFu5aiCxP0NP4rDzlC4x4TuTZ8I5Fs 4TgCfjY5xrupxnIjk4junm0cBQYBVjz9WiBnSZ3yGTkOZpPqhELnrMhzx8Q4U38g9mXe sW5w== X-Forwarded-Encrypted: i=1; AFNElJ8mDiZtlpuoeWlorPRP162eGqz4433NkE5IGz0iJlbUxPAtwjY3s7daUthFfzfSq7OTOvzFSisFDIrdiBg=@vger.kernel.org X-Gm-Message-State: AOJu0YzJJIEZsHjvk4kyB0sVTIUu9ZxGh6hPwOfTEJ3wdN/p2Zb+Hgd0 64hI3rncEjLjaxtAvRqMsrw89D+kgtKBoLI7dy73X7k836APHnModzq2yfh8QyrLakglinCOfY7 wpddfK+jaccJYvipDIM3UBZ4OflOlcM5z7cYxftL9dB+Oa5RmyQmqPbpIo3VoAWmBMXE= X-Gm-Gg: Acq92OHb/OxJlL4yoMnndaDv2/5QO13M1c3R9RC88vhLVwv3zg/8X/5zRlRvousDwWH 1fork4teeNP0/uuXA2c8TrQPw9roW6255t14qOHS1cqTUbVmSYYWrRqGucvtk2bwPotwGmoQ5/e p29dR3l0ZjLs4Wp0MV6ekqTFmtEvGqm/ddKJTzbAOMjBh3Nybh+WbfRzD3I6LzSNfFH4POo3+hT xPtqj7UXg6oyuE09vytYETCqixkR45j1PrC61o45s+FailjTZRxcS1OScYIv1ZhlWXrsZvBK8uI +28VGwCvWo5qzJQ83bXoCe6fdU69GA7GPm6XYHNPI2w/Z8XQsxTMHG7/7hYQH0L36RmPljpTolI 3pvK/ZrZbRpd8fXA1KNLYeu9KbmAOPRhpJO4l9ev38lj0ME5hG9y33rx+EcdLsw== X-Received: by 2002:a05:7300:5b9e:b0:304:ad0:e91 with SMTP id 5a478bee46e88-30734a41556mr828032eec.4.1780357437662; Mon, 01 Jun 2026 16:43:57 -0700 (PDT) X-Received: by 2002:a05:7300:5b9e:b0:304:ad0:e91 with SMTP id 5a478bee46e88-30734a41556mr828012eec.4.1780357437059; Mon, 01 Jun 2026 16:43:57 -0700 (PDT) Received: from [192.168.1.133] ([70.95.199.79]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-304ed53d14fsm10174697eec.17.2026.06.01.16.43.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 01 Jun 2026 16:43:56 -0700 (PDT) Message-ID: <7ab2b045-d93e-4a25-9ef2-ef34146fd53b@oss.qualcomm.com> Date: Mon, 1 Jun 2026 16:43:55 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] usb: dwc3: avoid probe deferral when USB power supply is not available To: Thinh Nguyen Cc: Greg Kroah-Hartman , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "jack.pham@oss.qualcomm.com" , "wesley.cheng@oss.qualcomm.com" References: <20260526183016.3501307-1-elson.serrao@oss.qualcomm.com> Content-Language: en-US From: Elson Serrao In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: U6-fMK81QEyRsLIcSN3iYp__cBFzRt5B X-Proofpoint-ORIG-GUID: U6-fMK81QEyRsLIcSN3iYp__cBFzRt5B X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjAxMDIzMiBTYWx0ZWRfXyFsYV4ia9j26 Pty3vQGHzIJiUOcMauTivnlrcfOWs/e699ndZi406PdiBUvCyDYwC/qpkUugiw6vxGEv0e3/0/m WQilUInS7ZER2P+EXFAHOe5q/d2zoZscH2IUOSm4cS1pX3W0ucfhir9noo5uQDUYGAXb4UZTO9C 04HNTwIz/Z7WnCJafRXk2+AUFLlhPlTS5saTBdpcyrRDJzOzPBodOiNzW5FwD4rbyrWSHP76vev dX+oKawNuZDXTb29BQMLKrnQVT4yqgopBigApZ6+VPWSpuh+0hLE++pMFiHJLfFGX7RoHtROJ54 qOpKWwXWVcUCD0JVQrfa3kTu8c8q3JECQJ0wITc0SXA7G6qmEB8B0pzH6JOG2x/hqY4p0PMJV+4 pxgEP8G9ZQl1AjUNgDDoKO9FvNoCXoAuK6OZ+kAj4XAeXh1SRbgbMaq9QW9Tp8tj+tnfKB2MJ3l vr4oWyetySubKONdDnA== X-Authority-Analysis: v=2.4 cv=P4YKQCAu c=1 sm=1 tr=0 ts=6a1e193e cx=c_pps a=Uww141gWH0fZj/3QKPojxA==:117 a=uHxescsG3rBdxcXwcPaeSg==:17 a=IkcTkHD0fZMA:10 a=FelO9ux0wxsA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=gowsoOTTUOVcmtlkKump:22 a=nBKuNKWrVJy6xT-lvhQA:9 a=QEXdDO2ut3YA:10 a=PxkB5W3o20Ba91AHUih5:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-06-01_06,2026-05-28_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 impostorscore=0 clxscore=1015 spamscore=0 lowpriorityscore=0 bulkscore=0 phishscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605210000 definitions=main-2606010232 On 5/27/2026 4:23 PM, Thinh Nguyen wrote: > On Tue, May 26, 2026, Elson Serrao wrote: >> The dwc3 driver currently defers probe if the USB power supply is not yet >> registered. On some platforms, even though charging and power supply >> functionality is available during normal operation, there may exist >> minimal booting modes (such as recovery or diagnostic environments) where >> the relevant USB power supply device is not registered. In such cases, >> probe deferral prevents USB gadget operation entirely. >> [...] >> + } >> + >> + dwc->usb_psy = psy; >> + if (dwc->current_limit != UINT_MAX) > > Create a macro for these kinds of checks for readability: > > #define DWC3_CURRENT_UNSPECIFIED UINT_MAX > Ack. [...] >> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >> index 3d4ca68e584c..303598048e9a 100644 >> --- a/drivers/usb/dwc3/gadget.c >> +++ b/drivers/usb/dwc3/gadget.c >> @@ -3124,15 +3124,21 @@ static void dwc3_gadget_set_ssp_rate(struct usb_gadget *g, >> static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA) >> { >> struct dwc3 *dwc = gadget_to_dwc(g); >> + unsigned long flags; >> >> if (dwc->usb2_phy) >> return usb_phy_set_power(dwc->usb2_phy, mA); >> >> - if (!dwc->usb_psy) >> + spin_lock_irqsave(&dwc->lock, flags); >> + dwc->current_limit = mA; >> + if (!dwc->usb_psy) { >> + spin_unlock_irqrestore(&dwc->lock, flags); >> + dev_dbg(dwc->dev, "Stored VBUS draw: %u mA (power supply not ready)\n", mA); > > Can we use the check if dwc->psy_nb.notifier_block is set to determine > if we expect to have a power_supply? Then we can print the message above > when it's really not ready, and only return -EOPNOTSUPP if we really > don't have a power_supply. > Hi Thinh, Just to clarify, in the case where dwc->psy_nb.notifier_call is set (i.e., we expect the power_supply but it is not available yet), should we return 0 and treat it as success since the current limit is cached and will be applied later? Or would you prefer returning an error (e.g., -ENODEV) to indicate to composite/upper layers that the current limit was not applied immediately (in case they need to observe this state)? Currently, we update gadget->mA only if this gadget op returns success. Returning 0 in this case would update gadget->mA even though the limit has not yet been applied. Thanks, Elson >> return -EOPNOTSUPP; >> + } >> >> - dwc->current_limit = mA; >> schedule_work(&dwc->vbus_draw_work); >> + spin_unlock_irqrestore(&dwc->lock, flags); >> >> return 0; >> } >> -- >> 2.34.1 >> > > The rest looks good to me. > > Thanks, > Thinh