From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4B0F9C4706C for ; Fri, 12 Jan 2024 14:33:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=bcmUBH1zM8kPZrllnxydVGPwq3Z4114pjl4EpO5TKp4=; b=sOY1apUfDuda5h Znkpbtu90GdbkKF3Zi4JkgpiLoZ+lIXLZD+Af/EHmhYvgUR6bELBtNkt9pBjzp3vKV6J9jPKm9ur4 QVvR4I4piAesuEPHsXti6yV9KdnnigAohzSA/wHrPRx2t0N3j0lOx2skexPPkgFcm7jfc9uM+Vwx0 xgKBgQXBcmW7ebTWrIlIWn/OQfRY9MseOUrj+2SKtZHfP6R0eyRwclQFRWeVc6bS2fdMXCQucV+p4 rRGZj0akjF0VqBnGlZyLtC6jPj4RbhPqkovP3UcvOqSGVaolASlbDd0UX1chVyjZez9s22UYmd6an ZKjk7XWVqE2AJNBKC5dw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rOIbF-0033H3-1U; Fri, 12 Jan 2024 14:33:33 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rOIbC-0033Es-18 for linux-arm-kernel@lists.infradead.org; Fri, 12 Jan 2024 14:33:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id CD4B3B822A0; Fri, 12 Jan 2024 14:33:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06FDEC433C7; Fri, 12 Jan 2024 14:33:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705070003; bh=JQFb0RwgqiOgAMfJwRMmXuTQbRDzY81oEPCIHnqCcqU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XECdFivIpDVFW8d+q1cmUj0ydJ04m25sDXk08JNeJU9TSTa+XzAfMKH3SZIOeywQg 4aqirrDf11dWd0P7Un0TmdFh9UgFGd+se/YhlLdw2i6EFN+ZqbzUUmC8gd+tViFnSs rJOHj8FRnqenuK9S2LGHVpS2Dr2HVNXE3U1Bbt89TSi6aTTuTyL3E283fecMbHdcyS Tm3tGHDglm8Dm+BKGjiEm03m7a+85u/yoB8pUaeKGTnaY9EkBT71dZAZ6lvduX6HqE DdDkCIVOlEd+oU6y/M4YdFspRKI98xxWM4F1t462Y8dTP4oFqXdf6jJU26l16G8ZvZ bvjQMuzu7vevg== Date: Fri, 12 Jan 2024 08:33:20 -0600 From: Rob Herring To: Vidya Sagar Cc: lpieralisi@kernel.org, kw@linux.com, bhelgaas@google.com, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, will@kernel.org, frowand.list@gmail.com, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, treding@nvidia.com, jonathanh@nvidia.com, kthota@nvidia.com, mmaddireddy@nvidia.com, sagar.tv@gmail.com Subject: Re: [PATCH V2 1/2] dt-bindings: Add PCIe "preserve-boot-config" property Message-ID: <20240112143320.GA3143039-robh@kernel.org> References: <20240110030725.710547-1-vidyas@nvidia.com> <20240110030725.710547-2-vidyas@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240110030725.710547-2-vidyas@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240112_063330_541562_843834F5 X-CRM114-Status: GOOD ( 19.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jan 10, 2024 at 08:37:24AM +0530, Vidya Sagar wrote: > The existing "linux,pci-probe-only" property applies at a system level > and it is not possible to selectively convey individual host bridge's > requirement w.r.t preserving the boot configuration done by the platform > firmware to the kernel. "preserve-boot-config" addresses that concern > and can be used to preserve the boot configuration for host bridges > selectivey. > > Signed-off-by: Vidya Sagar > --- > V2: > * None > > Documentation/devicetree/bindings/pci/pci.txt | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt > index 6a8f2874a24d..0a5ff998cbe8 100644 > --- a/Documentation/devicetree/bindings/pci/pci.txt > +++ b/Documentation/devicetree/bindings/pci/pci.txt > @@ -32,6 +32,10 @@ driver implementation may support the following properties: > root port to downstream device and host bridge drivers can do programming > which depends on CLKREQ signal existence. For example, programming root port > not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal. > +- preserve-boot-config: > + If present this property specifies that this host bridge is already > + configured by the platform firmware and the OS doesn't need to reconfigure > + it again. Anything new must be a schema. Don't create something new to workaround the problem. Extend the existing support. For this, make "linux,pci-probe-only" allowed in host bridge nodes. Yeah, there's the issue that this property sets a global flag, but I'd imagine the PCI maintainers would agree that some flags should/could be per bus. Rob _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel