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 EFF193446C7 for ; Mon, 9 Feb 2026 10:38:57 +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=1770633538; cv=none; b=EVZaECF3X1oaKOa+JvkOT//MgH1f9EmWobjLiBLx6YUji5xg1BL56uwAxxsHohwxnxy0PMvkfIfLDTS2RjcP+PQAdktj9HEFVk3jNoQRuWH9uvcesi4/XHLM8zfvfPVu8ewMdfbneXzYJkovwNVg7tPjJR0yTvmMPohQlIJZsak= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770633538; c=relaxed/simple; bh=WV7G7YLQc3fiwa1FcpbZ0kEYjyv316x4KMY+89ux7VQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LQU5E17i+F7fNAvL68MbfDR4+uyvUxPcDK1hBriC1hSewa/HHuKrVliRXNp1IMviEgGkkMP6au0AP9WUL2szcUvJrKek/GS9odwZi59ey9C4+0JrYmLvlWqBNmZNTj5/7IvYicBnTHgeApUFPwJerRWL0bjIbfD+Z8sVABr/pAw= 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=eMvOJA4r; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=cvFZ0tmV; 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="eMvOJA4r"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="cvFZ0tmV" Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 619A7l072600075 for ; Mon, 9 Feb 2026 10:38:57 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= c/jY10awzFduiO2n6GU3gHMcX31zAUtdN1QN5r7hFGo=; b=eMvOJA4rCNPHRIDw oz5UtpPbE1bMhDoVmSoBIP0/0aTMpbhxWNvXgyu4twf1uAmR2huBEkzst41Vn4ot rRNernD1MRgBgGwYUo829+MK8j92xLtbc/4fjp9uel5OPS2x6Q2uVCYqUF7fOgqs fDvir8zEbXsUtVnglLeszjnsTxS6qLFYtOoXDjYQoRtRtxlTEMEBTjdLSLzxis6q rv1DcKkAtUisWzlyKvXGLX23yqNnZPtVeghwlzS2te9Gj2bkQngyUejdMdX32iuX t7s0Y6mDvenAOtQdX0xJGMW4OH0vS97Dmh6Y7ndJ1ydq3eOmkySpwH5yT/t2TbU0 NLsCoA== Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4c78kh17gd-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Mon, 09 Feb 2026 10:38:56 +0000 (GMT) Received: by mail-qk1-f198.google.com with SMTP id af79cd13be357-8cb054b2f9eso138392185a.3 for ; Mon, 09 Feb 2026 02:38:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1770633536; x=1771238336; 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=c/jY10awzFduiO2n6GU3gHMcX31zAUtdN1QN5r7hFGo=; b=cvFZ0tmVftzi+omRIOmRSOWOQW56ckmWlSFJRHVA1AykzVyodNr2yJhTtjxVScHpjM f18+M4F1Fody5rOYW2jbkyBvMlK1BmBEhLMZ4Aw+gyxhcZGtOc4zk0zfzRB7JUJd+1mI F2Tb9YX5Gvuip/5Pa60wTnrK3vEUhSt/fLBVmBNXF7EtY/cZh9YcjYmjsUFl0nwPEGHe Yh1Ckh070m/rbEr/yE8IytmpIR3KsZdj37DHubkllV6NFekzg9Uo8+bGSWGWbr7EoWOY zI4xGfhgPvnqOjxJ3zT1O3Iv/zbiH4f66LRPEuzRsWX/ve2WydvEZR20Cdt+sDNUzQQ8 2nLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770633536; x=1771238336; 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=c/jY10awzFduiO2n6GU3gHMcX31zAUtdN1QN5r7hFGo=; b=T9X9gOCiy3xawQmLbsuOP9GJbBchZjsP0NoDe2G3E60hQUW6C2Tqz15nNEuB9n0dkx PyXu6HYgUGCNs9p/yXnrAXUtX6Ap6z5U5JpzjcaEAK2pywaV9z97nS9wKRub8ZNc0UBf rvIegN4MbjDsuXoUOOGxWO5Y9XSzGaTosBPPhz7plPp0Z+EtyUN9aus5P0/6cr2EB5FR vN43DX8Iork+nfBtmvoqMxyn0zietlVEWZD0duQRtth7To0WYsCIkXWGFna4QC0VPjzi P+itYPFGJD3X2HzWmd70yX2VYqYsxTnz8cVBDXW/L1WeSrIr+r/6vbMrK2a0TY+d0Mko yD7Q== X-Forwarded-Encrypted: i=1; AJvYcCVy3h2vN1V7wgCl3lLCUCNOBG1N3MCZGL2EiablbO+zfwDONsGe9Cy8Z+k11aaTN9Ic+JoltOxup6zW4GU=@vger.kernel.org X-Gm-Message-State: AOJu0Yx/M0aXJsvNDVda7V/43xo3xT646wRYgBqZpPoOE9FLIqFAhwOx wutHmUVVk5rEadXf73JET+Bvp6KpVQmi2juE+gcAt7MpsMZ3H6Z5uB+w35JmAaFst8cI7IBZCER ZOBVVABWaB0gSDRV4bqi2kbzAHADa1ajMeufSsnexBHaKzcPpy/SAzpEqF/bM8+iDguE= X-Gm-Gg: AZuq6aIiSyoLIBhFuColTKpSJ3w3efK0UE5t3VAFqbL6w8tku+lJuD9QY3RsLxplR4t h77qXUKkuP3DMhQfHd7TCPWNC15HAaSiCKQnZuYn7IKql0g4mYU89TLHCmGBWg+DJsd7o9pgmfd +uaaptGbM5fxz5CzVn41Jo3/HWcE7lnvQNFg7yf9WEAPWR+KRfGbzit5O0KfMUqSNoqtOrCnhXy fmXdNUetg/U1dVF8sH8WdOnFUo8zhxERwxRSihCCqZ+c5RPF04hHhroImC4issQ9/0mjx/+qdff foiF6XbBlCgjisLzPUtxvPQYyNcNAYYfTRlMNb5UIalKjHiYs4iM8IbSO0k47SiXnepa1E1ybqk 4itrZGrmFxaYg0JEVVSj8URc+3i7IuRILMEElHoeuBqhPegMyYjjk/4b+egE3/vp9slE= X-Received: by 2002:a05:620a:2906:b0:8b2:6eba:c45d with SMTP id af79cd13be357-8caeeb5115fmr1171647085a.2.1770633536099; Mon, 09 Feb 2026 02:38:56 -0800 (PST) X-Received: by 2002:a05:620a:2906:b0:8b2:6eba:c45d with SMTP id af79cd13be357-8caeeb5115fmr1171644885a.2.1770633535630; Mon, 09 Feb 2026 02:38:55 -0800 (PST) Received: from [192.168.119.254] (078088045245.garwolin.vectranet.pl. [78.88.45.245]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b8edae39441sm369817166b.59.2026.02.09.02.38.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Feb 2026 02:38:55 -0800 (PST) Message-ID: <2b86a7d4-7211-4154-a673-edc20d8c048b@oss.qualcomm.com> Date: Mon, 9 Feb 2026 11:38:53 +0100 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] of: property: Create devlink between PCI Host bridge and Root Port suppliers To: Saravana Kannan , Manivannan Sadhasivam Cc: robh@kernel.org, andersson@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, qiang.yu@oss.qualcomm.com References: <20260205070640.10653-1-manivannan.sadhasivam@oss.qualcomm.com> Content-Language: en-US From: Konrad Dybcio In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Authority-Analysis: v=2.4 cv=Nt7cssdJ c=1 sm=1 tr=0 ts=6989b940 cx=c_pps a=qKBjSQ1v91RyAK45QCPf5w==:117 a=FpWmc02/iXfjRdCD7H54yg==:17 a=IkcTkHD0fZMA:10 a=HzLeVaNsDn8A:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=Mpw57Om8IfrbqaoTuvik:22 a=GgsMoib0sEa3-_RKJdDe:22 a=EUspDBNiAAAA:8 a=VwQbUJbxAAAA:8 a=yl5-YIiGnJ5uwGII9rQA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=NFOGd7dJGGMPyQGDc5-O:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMjA5MDA4OSBTYWx0ZWRfX6bavKS9lT6hE 5Rc599C2qbft4+I9YFC5V8hLtOYWlZbjqcVz3vywTG0NoVFmbryy+ibwGOv/sCU0lyCsS1yOt2h nWslhjrT8UAzp+wFCIoN167JilRQe37J+6yNDmc3l/LkPKPum7+ewgjKv3vNOAW9cPP1c9x6jid 5T6hU2tKs2uHXnrM3Vry8kJRJ3HzdPnFi5sHkAmKsEGYS8b4a1egfhygNWVgcOR8DSx07UOWwny O777wOvRtURA1laWEbNNWijfUNyu2DzGKAFSSmzH580t8Hxz1E95qMNanT6Zr4zDzqFPjWT9GEx 2egvCh9KDfcZkUZEuJbfXyAK6qUHa1H1S7IoPuDEUOAghliAdJ/Ltz0lCk4qIcIx5Fa2x+BsqEm SJs06ckU++CiSpC0v7oEXB8bTY+ktyeUz4GKHziL2o68Fd6zISA3gfaaIQ2nOE+zHwVGMUYpoGu L5IBowSlTKB5ol0Poaw== X-Proofpoint-GUID: tPGgXp-7xekjIifDWCjLXkFGq_iE0pXS X-Proofpoint-ORIG-GUID: tPGgXp-7xekjIifDWCjLXkFGq_iE0pXS X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-02-08_05,2026-02-09_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 adultscore=0 malwarescore=0 bulkscore=0 suspectscore=0 clxscore=1015 priorityscore=1501 lowpriorityscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2601150000 definitions=main-2602090089 On 2/8/26 2:27 AM, Saravana Kannan wrote: > On Thu, Feb 5, 2026 at 1:01 AM Manivannan Sadhasivam > wrote: >> >> On Thu, Feb 05, 2026 at 09:50:20AM +0100, Konrad Dybcio wrote: >>> On 2/5/26 8:06 AM, Manivannan Sadhasivam wrote: >>>> In the recent times, devicetree started to represent the PCI Host bridge >>>> supplies like PHY in the Root Port nodes as seen in commit 38fcbfbd4207 >>>> ("dt-bindings: PCI: qcom: Move PHY & reset GPIO to Root Port node"). But >>>> the Host bridge drivers still need to control these supplies as a part of >>>> their controller initialization/deinitialization sequence. >>>> >>>> So the Host bridge drivers end up parsing the Root Port supplies in their >>>> probe() and controlled them. A downside to this approach is that the >>>> devlink dependency between the suppliers and Host bridge is completely >>>> broken. Due to this, the driver core probes the Host bridge drivers even if >>>> the suppliers are not ready, causing probe deferrals and setup teardowns in >>>> probe(). >>>> >>>> These probe deferrals sometime happen over 1000 times (as reported in Qcom >>>> Glymur platform) leading to a waste of CPU resources and increase in boot >>>> time. So to fix these unnecessary deferrals, create devlink between the >>>> Host bridge and Root Port suppliers in of_fwnode_add_links(). This will >>>> allow the driver core to probe the Host bridge drivers only when all Root >>>> Port suppliers are available. >>>> >>>> Reported-by: Bjorn Andersson >>>> Signed-off-by: Manivannan Sadhasivam >>>> --- >>> > > 100% NACK to this patch. You are touching a core part of the > fw_devlink code to fix it for one specific case. This is not the place > to special case for a property or a framework. I think the issue runs deeper. There are multiple cases where an OF node has children which represents sub-blocks of a hw block, and those may house e.g. a phy reference within. I'm not sure the code can handle this today. Konrad