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 X-Spam-Level: X-Spam-Status: No, score=-17.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3536CC433F5 for ; Tue, 7 Sep 2021 20:29:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C3B861152 for ; Tue, 7 Sep 2021 20:29:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346776AbhIGUaI (ORCPT ); Tue, 7 Sep 2021 16:30:08 -0400 Received: from gecko.sbs.de ([194.138.37.40]:33379 "EHLO gecko.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346600AbhIGU36 (ORCPT ); Tue, 7 Sep 2021 16:29:58 -0400 Received: from mail2.sbs.de (mail2.sbs.de [192.129.41.66]) by gecko.sbs.de (8.15.2/8.15.2) with ESMTPS id 187KSXW1005590 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 Sep 2021 22:28:33 +0200 Received: from [167.87.245.242] ([167.87.245.242]) by mail2.sbs.de (8.15.2/8.15.2) with ESMTP id 187KSWxs030398; Tue, 7 Sep 2021 22:28:32 +0200 Subject: Re: [PATCH 1/3] arm64: dts: ti: iot2050: Flip mmc device ordering on Advanced devices To: Aswath Govindraju , Nishanth Menon Cc: Tero Kristo , Rob Herring , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Bao Cheng Su , Chao Zeng References: <8e2e435ef67868cb98382b44c51ddb5c8d045d66.1631024536.git.jan.kiszka@siemens.com> <20210907151301.7fqwmc7hmcyhhybv@carve> <35e0cadf-526c-6402-fb8e-8cdb8b7a0bfe@siemens.com> <20210907152746.fbddtkktvx6hb5ti@cattishly> <20210907153547.53cc2zx23rx72kqf@thyself> <482dddc1-b1f8-15db-a0c5-0d6def5d859f@ti.com> <20210907165316.4s3jrouctcpc3kvo@pessimism> From: Jan Kiszka Message-ID: <4cb6e76e-479f-5e06-778a-4788be53afb9@siemens.com> Date: Tue, 7 Sep 2021 22:28:32 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07.09.21 19:01, Aswath Govindraju wrote: > Hi Nishanth, > > On 07/09/21 10:23 pm, Nishanth Menon wrote: >> On 22:17-20210907, Aswath Govindraju wrote: >>> Hi Nishanth, >>> >>> On 07/09/21 9:05 pm, Nishanth Menon wrote: >>>> On 17:30-20210907, Jan Kiszka wrote: >>>>> On 07.09.21 17:27, Nishanth Menon wrote: >>>>>> On 17:20-20210907, Jan Kiszka wrote: >>>>>>> On 07.09.21 17:13, Nishanth Menon wrote: >>>>>>>> On 16:22-20210907, Jan Kiszka wrote: >>>>>>>>> From: Jan Kiszka >>>>>>>>> >>>>>>>>> This ensures that the SD card will remain mmc0 across Basic and Advanced >>>>>>>>> devices, also avoiding surprises for users coming from the downstream >>>>>>>>> kernels. >>>>>>>>> >>>>>>>>> Signed-off-by: Jan Kiszka >>>>>>>>> --- >>>>>>>>> arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts | 5 +++++ >>>>>>>>> 1 file changed, 5 insertions(+) >>>>>>>>> >>>>>>>>> diff --git a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>>> index ec9617c13cdb..d1d5278e0b94 100644 >>>>>>>>> --- a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>>> +++ b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>>> @@ -18,6 +18,11 @@ / { >>>>>>>>> compatible = "siemens,iot2050-advanced", "ti,am654"; >>>>>>>>> model = "SIMATIC IOT2050 Advanced"; >>>>>>>>> >>>>>>>>> + aliases { >>>>>>>>> + mmc0 = &sdhci1; >>>>>>>>> + mmc1 = &sdhci0; >>>>>>>>> + }; >>>>>>>> >>>>>>>> >>>>>>>> Should we do this at SoC level? >>>>>>>> >>>>>>> >>>>>>> Well, I wouldn't mind - but that would also impact your EVMs. For us, >>>>>>> this is fine as we are coming from that ordering above with our >>>>>>> downstream kernel/dts. >>>>>>> >>>>>> >>>>>> I think it'd probably be a welcome change. overall we've standardized on >>>>>> partuuid. >>>>>> >>>>> >>>>> Yeah, it's more about "dd if=emmc.img of=/dev/mmcblk1 - damn, the wrong >>>>> one again." >>>>> >>>>> Let me know what you prefer, and I'll update my patch. >>>> >>>> >>>> Lets do it at SoC level. I will follow it up with a patch for other K3 >>>> SoCs as well. >>>> >>>> >>>> Unless someone has a strong opinion on this approach - if so, speak up >>>> with reasons. >>>> >>> >>> Making this change in SoC level for all K3 devices would force changes >>> to be made in U-Boot too, for consistency. In U-Boot, a major change >>> would be required in the environment variables to support this. As I >>> don't see any functional advantage by making this change, I feel that >>> this change would make things more confusing for users already using the >>> K3 devices. At present, the ordering is consistent across all the K3 >>> devices, I feel that keeping it the same way would be better. >>> >>> As for making changes only on IoT boards, if it is okay to have the >>> ordering changed between U-Boot and kernel, I don't see any problem >>> making this change in kernel alone. >> >> >> arch/arm64/boot/dts/ti/k3-am65.dtsi has no ordering. u-boot is supposed >> to copy from kernel the dtsi files as is. I think having mmc aliases in >> kernel is a good thing as we do regard kernel as the canonical dts >> source. >> > > Yes, you are correct. Aliases are not added for mmc in U-Boot too, but > due to the ordering in the device tree, mmc0 is always sdhci0 and mmc1 > is always sdhci1 in U-Boot. I agree that, in kernel as the probe order > is not guaranteed, fixing the order would be better by adding aliases > explicitly. > We had mmc reordered for our devices in U-Boot already. That separate snippet would obviously be obsolete when sync'ing common reordering over. >> If you are suggesting we flip things so that mmc0 is sdhci0 and mmc1 is >> sdhci1 - that might be a valid suggestion - Jan, do you see a problem >> in having consistency here (flip the aliases)? >> >> > > Yes, I am suggesting a flip in the order and this order can be applied > across all the K3 SoC's > I'm not sure what you are suggesting. I've sent v2 already which moves aliasing to SoC level, and I would push that to U-Boot as well if acceptable. If not, we will keep this in our board DTs. Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux