From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f173.google.com (mail-pf1-f173.google.com [209.85.210.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C466D18A925; Sat, 2 Nov 2024 14:19:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730557161; cv=none; b=urONHNihTj4xFkxCYMKFGET1Ybx3Hr0C53TjB+96NKlm1TWwqAPCfN7US/DYHj4aZRsJ7tX2SJOT8oiEROVG1njMABKbcwT7HR4zpDZQZYb3DKqSxTEhsZ+OhJP+RuLufTj5h6DuX1xLPe8C1XeJ3g5EF4XygK1xU3Gz+ni4rhU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730557161; c=relaxed/simple; bh=i4VUhHPhcihVwDXVjt1X6R/W0FnDjTq2LIn5IcgTqe0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=edJFIGgSCi30AxsZAIJ9NPYC4MoBEbqzc367YCIF0pIUy5Ma+Kn5EdkUnzgSVn87UMT4PpOnK4Cwik0K4AFi57hZ6mOdtrie68OvMA7PtUUgXmwy6BLmEcYpUmeTLgcUpvl0qXm7l0n9kgtN40tej8RgM3SPCYU4KcU0hm77mN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.com; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.210.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pf1-f173.google.com with SMTP id d2e1a72fcca58-71e983487a1so2456399b3a.2; Sat, 02 Nov 2024 07:19:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730557157; x=1731161957; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=RoNhd3PU7MNVWI+sf1DSija4VTsLivchGzEQ82Up2A4=; b=cPmrYyIa55ThLP4WAwzIA2ce5QvaJjOvLZ7TBc/WR/dLgAzCe7f2toPst2d03hOO8x 9ZBultzA7uMjKnTV8Tk+McEi1V57zJR2siW0K7F1yI2JoW4H3xWhEYyl+4d5tS8O/YcE ibrPTWOrur/XcKjedUmUibOKl3CvIRsvsxa8J/Mk9pvSjN+M/ApbFXzQTqOBDQO3FcVt aLas0EIOMihXR56tGSkgPU/kjU9ph1fKS2T6+C+dtx2Lx/wQvI0Bj9jz2BqVsHIARykV P37kDaPx0R2y3e2CKaOUO3C4/l9L9BAaZe2cIFZPgVXR46sJknrzW9REAijcuLi7WPj6 /D9Q== X-Forwarded-Encrypted: i=1; AJvYcCWHrqbBCKNcQf+OEunbRuBztdZO4szLk2IZ6ptw9QrrU+t+YZq8I9gZDjAull5EDZ4gIoE2kXVC6y7l@vger.kernel.org, AJvYcCWZoWAxn1kB+JtiuG8aceeybOgsvddqRPWFhrEU00ATPB1F9QtlixNwQIpRYQoUgawDvDuAHl6rNjQyw6M=@vger.kernel.org, AJvYcCXIkD3XmMhdGskFxsrMhuy4GDBlFbt7edZNlQnc/0SSPg1jPgg/WPSvzHiWljEzxFnQEs+aRGfXKUyBsg==@vger.kernel.org X-Gm-Message-State: AOJu0Yy/IbRvdCVJ+YCTGH+ohfLDNrPqhfU8Kt9x/WpBd5r9Bey1JgrF hl/oDqmi4BG7/NiSB9SON/nIJHsOUHiF+XyuSsc9rF6E/mvSLZmS X-Google-Smtp-Source: AGHT+IHPcKNMt6OSC6S/K2FJ3EposZZ5TOsaoIOHKw561pjEChI1kIfOypmeQ6NBttJJZ5y0zs9rDw== X-Received: by 2002:a05:6a00:2ea5:b0:71e:82b4:6e6e with SMTP id d2e1a72fcca58-720b9bb3edbmr14950575b3a.4.1730557157041; Sat, 02 Nov 2024 07:19:17 -0700 (PDT) Received: from localhost (fpd11144dd.ap.nuro.jp. [209.17.68.221]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-720bc2c3902sm4096567b3a.136.2024.11.02.07.19.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 02 Nov 2024 07:19:16 -0700 (PDT) Date: Sat, 2 Nov 2024 23:19:14 +0900 From: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= To: Siddharth Vadapalli Cc: bhelgaas@google.com, lpieralisi@kernel.org, robh@kernel.org, vigneshr@ti.com, manivannan.sadhasivam@linaro.org, thomas.richard@bootlin.com, linux-omap@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, srk@ti.com Subject: Re: [PATCH] PCI: j721e: Deassert PERST# after a delay of PCIE_T_PVPERL_MS ms Message-ID: <20241102141914.GA3440781@rocinante> References: <20241022083147.2773123-1-s-vadapalli@ti.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241022083147.2773123-1-s-vadapalli@ti.com> Hello, > According to Section 2.2 of the PCI Express Card Electromechanical > Specification (Revision 5.1), in order to ensure that the power and the > reference clock are stable, PERST# has to be deasserted after a delay of > 100 milliseconds (TPVPERL). Currently, it is being assumed that the power > is already stable, which is not necessarily true. Hence, change the delay > to PCIE_T_PVPERL_MS to guarantee that power and reference clock are stable. [...] > This patch is based on commit > c2ee9f594da8 KVM: selftests: Fix build on on non-x86 architectures > of Mainline Linux. Why KVM? Do you have the link to this commit handy? [...] > if (pcie->reset_gpio) { > - fsleep(PCIE_T_PERST_CLK_US); > + msleep(PCIE_T_PVPERL_MS); fsleep() with the same macro and for the same reason is also used in the j721e_pcie_probe() callback. I think, we would want both changed. Krzysztof