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 6D3E632ED3E for ; Thu, 13 Nov 2025 07:48:13 +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=1763020095; cv=none; b=juYB69Kq/9Hj1la0TVAumB99jM1U4Foog3gdns6h35z4q3Y/ucGqNtf2F0kJAWohh3JjkRm9KV+rzNF+gbznex8ww0WnPBaApbdIeq0Xvn0ZEk7Jl1BLwirT+BL5yOtnj6Zy/QkDICjH2hKl6hmX2yXD1wo3q8pSEREPfuiDCrQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763020095; c=relaxed/simple; bh=vFb2M/nGxgnEBD9w5S2ekv3idrtEuY3kFjlfebSCyeg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Cmj2C3PJyQaiSy8eIKUiHhhJPSMtHpuqhdLbXKZW22qAFA+PUaJVwdBeqVU/sk/J7AckCx23Hv7rxZtJYxDHQkENn+T4LMGpOQdriPCf2KQGWxzQTW/9OsuaikR9tSsnfYtD//aqFz51y9vE8VcYku4U8IAHk0twPAkoOoPGQEo= 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=bUev4afq; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=evpGfOT4; 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="bUev4afq"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="evpGfOT4" 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 5AD5S6bS3440445 for ; Thu, 13 Nov 2025 07:48:12 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= ZhJiozGc7U8ZGJ8uF2XWeIPBKlSbzOs14hlPqFLDlL0=; b=bUev4afqfG1rIKXk adLozXY4vwGey3rmYhB7jvaFd4QdWpywYz0fC2ZUySlVflX6gn5Kk3rrMnw+5Qg+ T6UJV396b3J+dRotjg2muurlmmslNjiTZxLPY4QNOP6T4KjJIfxGEQ1IDtqSIm9+ +HqWEZA7ZOQUmw8ta6QjliNsBVHuWoQO74XEGqQ9973z7QavTew8F4ik2hLgiROC 0kI/ZJM4aSgNA8zR0tXJ3R4AjfR59nTGdlqoQ9T6RDYgeMcR38/tFR5VipCDGm+Y aFO0MwvDpyLyD4436+u6cO2ah4LtDYie4ybWLK5FyA9N9oQWXAjHZBiw2PGkqxIU bAYq2Q== Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4ad9788djf-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Thu, 13 Nov 2025 07:48:12 +0000 (GMT) Received: by mail-pl1-f200.google.com with SMTP id d9443c01a7336-295592eb5dbso6559485ad.0 for ; Wed, 12 Nov 2025 23:48:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1763020091; x=1763624891; 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=ZhJiozGc7U8ZGJ8uF2XWeIPBKlSbzOs14hlPqFLDlL0=; b=evpGfOT4PWoMD+LQj99PQtAObLm89GzULZm1xLVaIjrCzyTewg2DL12hyufRmgsQDA ypQjbeONOFFY9OJXMh5z8UWmri0T0BnNgZjaApT26r2wsqdnNgy6uhPno4Oyi1LQDy2Q +pBtive8gHlyIo8ZMPYhodGw6R0zWSsfgaTPopsOoh/Nh+RBmNO1JeBKe/0MfsPxZ0I2 ZaFQXZ5Nd8zABm9mbb8AaeWZq6WIFyUQoTxWcZbm8i/PB7PA+ads6SAigF6ZAILKpj/h 07QBTVCQp5dhQJ9MqqNPMG8jV6Bbup/eyt/myMjJuBZiCJYJg8TGlcyP7Cy4P/ijS2ee SBuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763020091; x=1763624891; 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=ZhJiozGc7U8ZGJ8uF2XWeIPBKlSbzOs14hlPqFLDlL0=; b=kDbe1wMjv/qD699Yk8EFWmW1J0LmZIkwkXi1gw57Uh5DmDtDgIc+RxVLxlfcDFJys9 fHVICUvuWl2xkd7bQVRFEonzI0cWFAkw55VFl1DaWxpUrJHiOvZBdjx6Xtn0Y4LiJkhL RZM2YFdQTGuV/FkzoVeeg2cz6O5xg3mktcT2kPLS2M2/vDleHTwDDutRHGcptMr+t7Em 6YRH0vjs2OkqM29N9wQufrV8ebbkPNYiCl/bIb2lTreG5bvZkGod+DbSELjVlxX6rgH7 5/KjnrRvqcavSG/qwbjX8xabQIeG4QkFxtmEJ4fyeH7eMXcsQpCntBY81+sQcnrS4olg 8Eqw== X-Forwarded-Encrypted: i=1; AJvYcCWEFS4SmonrUW2UMEqCIpBAOkWtQGT9JNTOjsmbmdKnFIuwzn2nAjFxx1bj9LWp5ztQyxJ7TuqURQqyI7Y=@vger.kernel.org X-Gm-Message-State: AOJu0Yxy2KHIO7TmhmK8d9Xxa+wDoplOdEw8F/BpGx6zz5vekjcWBjjO vDn+aOWu/EE8RV59XOiuzMUkOJH1RHmaqd6S00UiV5hn0xuYhMrUhwuzZ5WkkaCI2plbF0Zp0uK mSJ0Pks+t5z/4PXr2XncrykeulcI2MofjRyKErlEjDYrIVNbFjDWdk66BHHwIEExE6k2uuH/FiV 0= X-Gm-Gg: ASbGncu/nQDW08zH2SwArnIZZWAzFyBYFN2HgqBLkbvfzuLQs+zX9/tabjcrctGVKjE pBWjQ0zZZE28MK/92LrTUgEkArgjvJT6ObpKrnGDjvnuKQsY99cmWO/8x1OJSUxuYCC1fVZ9Q3F hChfGhraxrRvo/UJgPlDqfa2t69+FL+2/18mCbDx+VEbOj0MHnjTHCKZj3U0CqsSGUt9LQaLG2P zjZG8nnspMQ3q4/YdXiEjMBT63j/rMMS7WlwJnmQPcFjuZzIDKToIumL5WExJ8BWM5p7XNM2GBI D26VE78N12kUiikySzACKq38tF0z5PvaDNeIiXv4ZWZxh/21S1KGYEIOqskTXzBH+aJhz23h/P+ JxdOY4CKHnL3rKGhc1iF/AW+BSaEAS/k= X-Received: by 2002:a17:902:ebc6:b0:298:495c:1bf0 with SMTP id d9443c01a7336-2984edd2700mr69775655ad.44.1763020091151; Wed, 12 Nov 2025 23:48:11 -0800 (PST) X-Google-Smtp-Source: AGHT+IF8rRkEuWW/6gSHvrkhgOhcnbTpcGFokK+8H6N4ylsRW3aMFxk3k4phtF2p1olCGtMTmr/Plw== X-Received: by 2002:a17:902:ebc6:b0:298:495c:1bf0 with SMTP id d9443c01a7336-2984edd2700mr69775255ad.44.1763020090661; Wed, 12 Nov 2025 23:48:10 -0800 (PST) Received: from [10.218.35.45] ([202.46.22.19]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2985c2bed5asm15548045ad.88.2025.11.12.23.48.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Nov 2025 23:48:10 -0800 (PST) Message-ID: <9dbae7ca-b24f-4591-99cf-7720ace6a452@oss.qualcomm.com> Date: Thu, 13 Nov 2025 13:18:04 +0530 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] schemas: pci: Document PCIe T_POWER_ON To: Manivannan Sadhasivam Cc: andersson@kernel.org, robh@kernel.org, krzk@kernel.org, helgaas@kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, lpieralisi@kernel.org, kw@linux.com, conor+dt@kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree-spec@vger.kernel.org, quic_vbadigan@quicinc.com References: <20251110112947.2071036-1-krishna.chundru@oss.qualcomm.com> Content-Language: en-US From: Krishna Chaitanya Chundru In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTEzMDA1NCBTYWx0ZWRfX5gV7pAtSLciA fjCe8813I6YLRAazpuGvMNPNapUGvsYkxE7gZvcNWt/VNaArS83rM7wFl+NapWtHhSjV1heyxYU LhPruZZUSWMuI7I77k2opgN4GA4K005iK2Xc+8088MVD861uze5fHR+MXaC17XXD6OM7H3RP6Ha S0RJRObDLYXuhPvujVPmfzyqZPuCERdsjXtxyaRNdZ+AGtC3B0izCCP8XZVNxJU2j/gMOHtoOv7 MGqyoqs8tRRFbM5cgGR1LFixwLwAQhi22OjyURyeynLi3WmwlthWY+iX9/vtdGo65dVa/1HLrM2 Cw6Pgbl+Tr+PLp342KMPJi5UEWT1PXJ4nQb9ActmGb/JxNovXmSvh4Zm7SIRpDPlNBZ3NRJWHtR m/3bRJvfHdRMRcOyVTlKXYuRqHGqDw== X-Proofpoint-ORIG-GUID: xTvysJiMEwfYPHVvsuxKFQ6PVQihO1nX X-Proofpoint-GUID: xTvysJiMEwfYPHVvsuxKFQ6PVQihO1nX X-Authority-Analysis: v=2.4 cv=PIYCOPqC c=1 sm=1 tr=0 ts=69158d3c cx=c_pps a=IZJwPbhc+fLeJZngyXXI0A==:117 a=fChuTYTh2wq5r3m49p7fHw==:17 a=IkcTkHD0fZMA:10 a=6UeiqGixMTsA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=EUspDBNiAAAA:8 a=5gsRW-pyyPTur7QFVg0A:9 a=QEXdDO2ut3YA:10 a=uG9DUKGECoFWVXl0Dc02:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-11-12_06,2025-11-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 suspectscore=0 spamscore=0 adultscore=0 clxscore=1015 lowpriorityscore=0 phishscore=0 bulkscore=0 impostorscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2510240001 definitions=main-2511130054 On 11/10/2025 5:33 PM, Manivannan Sadhasivam wrote: > On Mon, Nov 10, 2025 at 04:59:47PM +0530, Krishna Chaitanya Chundru wrote: >> From PCIe r6, sec 5.5.4 & Table 5-11 in sec 5.5.5 T_POWER_ON is the >> minimum amount of time(in us) that each component must wait in L1.2.Exit >> after sampling CLKREQ# asserted before actively driving the interface to >> ensure no device is ever actively driving into an unpowered component and >> these values are based on the components and AC coupling capacitors used >> in the connection linking the two components. >> >> This property should be used to indicate the T_POWER_ON for each Root Port. >> > I'm not sure if we should restrict this property to just Root Ports. Defining a > property in 'pci-bus-common.yaml' means, all PCI bridges could use it, but this > value is applicable to endpoint devices also. Better to add in pci-device.yaml then. > Also, you might want to add some info that the driver (or DT consumer) should > derive the T_POWER_ON Scale and T_POWER_ON Value from this value. ack - Krishna Chaitanya. > - Mani > >> Signed-off-by: Krishna Chaitanya Chundru >> --- >> Changes in v1: >> - Updated the commiit text (Mani). >> - Link to v1: https://lore.kernel.org/all/20251110112550.2070659-1-krishna.chundru@oss.qualcomm.com/#t >> >> dtschema/schemas/pci/pci-bus-common.yaml | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/dtschema/schemas/pci/pci-bus-common.yaml b/dtschema/schemas/pci/pci-bus-common.yaml >> index 5257339..bbe5510 100644 >> --- a/dtschema/schemas/pci/pci-bus-common.yaml >> +++ b/dtschema/schemas/pci/pci-bus-common.yaml >> @@ -152,6 +152,15 @@ properties: >> This property is invalid in host bridge nodes. >> maxItems: 1 >> >> + t-power-on-us: >> + description: >> + The minimum amount of time that each component must wait in >> + L1.2.Exit after sampling CLKREQ# asserted before actively driving >> + the interface to ensure no device is ever actively driving into an >> + unpowered component. This value is based on the components and AC >> + coupling capacitors used in the connection linking the two >> + components(PCIe r6.0, sec 5.5.4). >> + >> supports-clkreq: >> description: >> If present this property specifies that CLKREQ signal routing exists from >> -- >> 2.34.1 >> >>