From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A71F67A for ; Fri, 8 Jul 2022 09:47:52 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 32615D6E; Fri, 8 Jul 2022 02:47:52 -0700 (PDT) Received: from donnerap.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 863B93F66F; Fri, 8 Jul 2022 02:47:50 -0700 (PDT) Date: Fri, 8 Jul 2022 10:47:46 +0100 From: Andre Przywara To: Samuel Holland Cc: Jernej =?UTF-8?B?xaBrcmFiZWM=?= , Chen-Yu Tsai , Rob Herring , Krzysztof Kozlowski , Icenowy Zheng , linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v11 3/6] arm64: dts: allwinner: Add Allwinner H616 .dtsi file Message-ID: <20220708104746.6623e239@donnerap.cambridge.arm.com> In-Reply-To: <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> References: <20220428230933.15262-1-andre.przywara@arm.com> <22699277.6Emhk5qWAg@kista> <20220704225534.3e1a901a@slackpad.lan> <5278570.Sb9uPGUboI@kista> <20220706141655.15d2dd0e@donnerap.cambridge.arm.com> <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> Organization: ARM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 7 Jul 2022 01:30:32 -0500 Samuel Holland wrote: Hi Samuel, > Hi Andre, Jernej, > > On 7/6/22 8:16 AM, Andre Przywara wrote: > > so after seemingly having finished writing this email, I realised that > > this won't really help, as I think this diverts the discussion. And the > > problem has been around for a while, and won't probably be solved easily > > or quickly. I think we agree to disagree here, or we should admit that > > there are different approaches ("bundled firmware" vs. "UEFI"), so in the > > interest of not blocking the H616 series: > > > > Shall I just keep the firmware node? This would work both ways, whereas > > dropping the node would impede the "bundled firmware" approach? > > Let me try to sum up the relevant portion of my thoughts (and save the rest for > elsewhere): > > The only reason to add the reserved-memory node is to support externally-loaded > DTBs. By adding the node, we are committing to support externally-loaded DTBs on > this SoC. > > Upgrading the kernel is not allowed to break boot. If we support > externally-loaded DTBs, that rule extends to DTBs shipped with the kernel. > > If we remove the reserved-memory node, the combination of old U-Boot + new > externally-loaded DTB will stop booting (the kernel version is irrelevant). > Therefore, if we add the node, we can never remove it, full stop. Well, this all depends on the initial commitment to support externally-loaded DTBs. I don't think we need to make this promise, I'd rather see this as a concession to people doing so *right now*, and for the sheer practicality of using this DT until we merge it into U-Boot. > I will (begrudgingly) accept that, as long as the node matches what TF-A > actually generates today. That means, please: > - Drop the label and update the node name I will drop the label. For the node name: the binding does not enforce it, but asks that "node names should reflect the purpose", so I went with "secmon", as used by other platforms. I will send a patch to TF-A to fix it there instead. If you disagree, feel free to fix this up before committing. > - Reduce the size to 256 KiB, matching (BL31_LIMIT - BL31_BASE) Verified in TF-A and changed. I also added a short comment explaining the situation. Feel free to amend this if needed. Many thanks for the discussion and for resolving this. I much appreciate your flexibility and pragmatism in this matter! Cheers, Andre 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 0D888C43334 for ; Fri, 8 Jul 2022 09:48:52 +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:MIME-Version:References:In-Reply-To: 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=FjGwxwxhQt1K/LSUaCdzZ1UVMKTAFtgCPfZ73iTZIKc=; b=f3FWFHTVybXM1e PUj2DcMfJevCKQj+n3m/U4sgE3mk3or8zzIWApwQ0iplL6MvMNyQ9InpQcMBzUuV0cf4tGzzKLEsQ G75DxAhS5cOAigKVcZyrTApu4LfVbdXNhtI6pWmOc3G32URsX1/in9edYuFcGUBXyUhO/vhGvFuIz iIj0dO9LrQToV0REpbozrUv6f1kvgQ89/Km/0YOSCMa3aNz8+8fhSKLIT0Gj812N/iJ6Sof7NNDaB JlTpOK4iL7SU2We8VPOnXYWNsJBa1UtRVXjgJpwdrLMaqQAEnPmIvi96qw9Kh0jxYmzQl4TV04s0h oOjl9CUdynIBwC7cZHfg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o9kab-0030Pj-HG; Fri, 08 Jul 2022 09:47:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o9kaY-0030P8-5x for linux-arm-kernel@lists.infradead.org; Fri, 08 Jul 2022 09:47:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 32615D6E; Fri, 8 Jul 2022 02:47:52 -0700 (PDT) Received: from donnerap.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 863B93F66F; Fri, 8 Jul 2022 02:47:50 -0700 (PDT) Date: Fri, 8 Jul 2022 10:47:46 +0100 From: Andre Przywara To: Samuel Holland Cc: Jernej =?UTF-8?B?xaBrcmFiZWM=?= , Chen-Yu Tsai , Rob Herring , Krzysztof Kozlowski , Icenowy Zheng , linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v11 3/6] arm64: dts: allwinner: Add Allwinner H616 .dtsi file Message-ID: <20220708104746.6623e239@donnerap.cambridge.arm.com> In-Reply-To: <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> References: <20220428230933.15262-1-andre.przywara@arm.com> <22699277.6Emhk5qWAg@kista> <20220704225534.3e1a901a@slackpad.lan> <5278570.Sb9uPGUboI@kista> <20220706141655.15d2dd0e@donnerap.cambridge.arm.com> <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> Organization: ARM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220708_024754_328953_49D24F2E X-CRM114-Status: GOOD ( 28.59 ) 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 Thu, 7 Jul 2022 01:30:32 -0500 Samuel Holland wrote: Hi Samuel, > Hi Andre, Jernej, > > On 7/6/22 8:16 AM, Andre Przywara wrote: > > so after seemingly having finished writing this email, I realised that > > this won't really help, as I think this diverts the discussion. And the > > problem has been around for a while, and won't probably be solved easily > > or quickly. I think we agree to disagree here, or we should admit that > > there are different approaches ("bundled firmware" vs. "UEFI"), so in the > > interest of not blocking the H616 series: > > > > Shall I just keep the firmware node? This would work both ways, whereas > > dropping the node would impede the "bundled firmware" approach? > > Let me try to sum up the relevant portion of my thoughts (and save the rest for > elsewhere): > > The only reason to add the reserved-memory node is to support externally-loaded > DTBs. By adding the node, we are committing to support externally-loaded DTBs on > this SoC. > > Upgrading the kernel is not allowed to break boot. If we support > externally-loaded DTBs, that rule extends to DTBs shipped with the kernel. > > If we remove the reserved-memory node, the combination of old U-Boot + new > externally-loaded DTB will stop booting (the kernel version is irrelevant). > Therefore, if we add the node, we can never remove it, full stop. Well, this all depends on the initial commitment to support externally-loaded DTBs. I don't think we need to make this promise, I'd rather see this as a concession to people doing so *right now*, and for the sheer practicality of using this DT until we merge it into U-Boot. > I will (begrudgingly) accept that, as long as the node matches what TF-A > actually generates today. That means, please: > - Drop the label and update the node name I will drop the label. For the node name: the binding does not enforce it, but asks that "node names should reflect the purpose", so I went with "secmon", as used by other platforms. I will send a patch to TF-A to fix it there instead. If you disagree, feel free to fix this up before committing. > - Reduce the size to 256 KiB, matching (BL31_LIMIT - BL31_BASE) Verified in TF-A and changed. I also added a short comment explaining the situation. Feel free to amend this if needed. Many thanks for the discussion and for resolving this. I much appreciate your flexibility and pragmatism in this matter! Cheers, Andre _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel