On 19/05/2022 13:44, Krzysztof Kozlowski wrote:
Hi, There was an old effort of removal of qcom,board-id and qcom,msm-id properties from Qualcomm SoC-based boards like [1]. First approach was to document them, which (obviously) was not well received [2] [3] [4]. The solution from Stephen was to encode these in the board compatible, so bootloader can extract that information. That seemed to receive positive comments, at least from Rob. [5] It was 2015... ~7 years later we are still things doing the same way, still with undocumented properties: qcom,board-id and qcom,msm-id. I would like to revive that topic, but before I start doing something pointless - any guidance on last patch from Stephen [5]? Was it ok? Some early NAKs?
I do not quite fancy the idea of using extra tools to process dtb files. At this moment it is possible to concatenate several kernel-generated dtb files together. AOSP developers use this to have an image that boots on both RB3 and RB5 boards.
I think that changing compat strings only makes sense if Qualcomm would use such compat strings in future. Otherwise we end up in a position where we have custom bootloaders for the RB3/RB5/etc, but the majority of the board requires extra processing steps.
So, I think, we should drop the unspecified usid aliases, document the board-id/msm-id/pmic-id properties and stick with them. They might be ugly, but they are expected/processed by the majority of devices present in the wild.
[1] https://elixir.bootlin.com/linux/v5.18-rc7/source/arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts#L14 [2] https://lore.kernel.org/all/7229476.C4So9noUlf@wuerfel/ [3] https://lore.kernel.org/all/1450371534-10923-20-git-send-email-mtitinger+renesas@xxxxxxxxxxxx/ [4] https://lore.kernel.org/all/20151119153640.GC893@xxxxxxxxxx/ [5] https://lore.kernel.org/all/1448062280-15406-1-git-send-email-sboyd@xxxxxxxxxxxxxx/ Best regards, Krzysztof
-- With best wishes Dmitry
