From: Andre Przywara <andre.przywara@arm.com> To: Samuel Holland <samuel@sholland.org> Cc: "Jernej Škrabec" <jernej.skrabec@gmail.com>, "Chen-Yu Tsai" <wens@csie.org>, "Rob Herring" <robh@kernel.org>, "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>, "Icenowy Zheng" <icenowy@aosc.io>, 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 Date: Fri, 8 Jul 2022 10:47:46 +0100 [thread overview] Message-ID: <20220708104746.6623e239@donnerap.cambridge.arm.com> (raw) In-Reply-To: <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> On Thu, 7 Jul 2022 01:30:32 -0500 Samuel Holland <samuel@sholland.org> 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
WARNING: multiple messages have this Message-ID (diff)
From: Andre Przywara <andre.przywara@arm.com> To: Samuel Holland <samuel@sholland.org> Cc: "Jernej Škrabec" <jernej.skrabec@gmail.com>, "Chen-Yu Tsai" <wens@csie.org>, "Rob Herring" <robh@kernel.org>, "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>, "Icenowy Zheng" <icenowy@aosc.io>, 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 Date: Fri, 8 Jul 2022 10:47:46 +0100 [thread overview] Message-ID: <20220708104746.6623e239@donnerap.cambridge.arm.com> (raw) In-Reply-To: <39537f95-2ed4-f526-5912-364c1c1ed512@sholland.org> On Thu, 7 Jul 2022 01:30:32 -0500 Samuel Holland <samuel@sholland.org> 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
next prev parent reply other threads:[~2022-07-08 9:47 UTC|newest] Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-28 23:09 [PATCH v11 0/6] arm64: sunxi: Initial Allwinner H616 SoC support Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-04-28 23:09 ` [PATCH v11 1/6] clk: sunxi-ng: h6-r: Add RTC gate clock Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-05-03 2:06 ` Samuel Holland 2022-05-03 2:06 ` Samuel Holland 2022-05-06 16:10 ` Jernej Škrabec 2022-05-06 16:10 ` Jernej Škrabec 2022-04-28 23:09 ` [PATCH v11 2/6] clk: sunxi-ng: h616: Add PLL derived 32KHz clock Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-05-06 16:11 ` Jernej Škrabec 2022-05-06 16:11 ` Jernej Škrabec 2022-04-28 23:09 ` [PATCH v11 3/6] arm64: dts: allwinner: Add Allwinner H616 .dtsi file Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-05-03 19:05 ` Jernej Škrabec 2022-05-03 19:05 ` Jernej Škrabec 2022-05-03 19:41 ` Jernej Škrabec 2022-05-03 19:41 ` Jernej Škrabec 2022-06-30 0:04 ` Andre Przywara 2022-06-30 0:04 ` Andre Przywara 2022-07-02 21:16 ` Jernej Škrabec 2022-07-02 21:16 ` Jernej Škrabec 2022-07-04 13:30 ` Andre Przywara 2022-07-04 13:30 ` Andre Przywara 2022-07-04 18:42 ` Jernej Škrabec 2022-07-04 18:42 ` Jernej Škrabec 2022-07-04 21:58 ` Andre Przywara 2022-07-04 21:58 ` Andre Przywara 2022-07-05 17:32 ` Jernej Škrabec 2022-07-05 17:32 ` Jernej Škrabec 2022-07-06 13:16 ` Andre Przywara 2022-07-06 13:16 ` Andre Przywara 2022-07-07 6:30 ` Samuel Holland 2022-07-07 6:30 ` Samuel Holland 2022-07-07 16:39 ` Jernej Škrabec 2022-07-07 16:39 ` Jernej Škrabec 2022-07-08 9:47 ` Andre Przywara [this message] 2022-07-08 9:47 ` Andre Przywara 2022-07-04 18:44 ` Samuel Holland 2022-07-04 18:44 ` Samuel Holland 2022-07-04 20:52 ` Andre Przywara 2022-07-04 20:52 ` Andre Przywara 2022-04-28 23:09 ` [PATCH v11 4/6] dt-bindings: arm: sunxi: Add two H616 board compatible strings Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-04-28 23:09 ` [PATCH v11 5/6] arm64: dts: allwinner: h616: Add OrangePi Zero 2 board support Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-05-03 19:41 ` Jernej Škrabec 2022-05-03 19:41 ` Jernej Škrabec 2022-06-30 0:08 ` Andre Przywara 2022-06-30 0:08 ` Andre Przywara 2022-04-28 23:09 ` [PATCH v11 6/6] arm64: dts: allwinner: h616: Add X96 Mate TV box support Andre Przywara 2022-04-28 23:09 ` Andre Przywara 2022-05-03 19:44 ` Jernej Škrabec 2022-05-03 19:44 ` Jernej Škrabec
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