[CCing the regression list, as it should be in the loop for regressions: https://docs.kernel.org/admin-guide/reporting-regressions.html] On 10.04.23 08:06, Ricardo Cañuelo wrote: > Culprit: > https://lore.kernel.org/r/20211227180026.4068352-2-martin.blumenstingl@xxxxxxxxxxxxxx > > On lun 27-12-2021 19:00:24, Martin Blumenstingl wrote: >> The dt-bindings for the UART controller only allow the following values >> for Meson6 SoCs: >> - "amlogic,meson6-uart", "amlogic,meson-ao-uart" >> - "amlogic,meson6-uart" >> >> Use the correct fallback compatible string "amlogic,meson-ao-uart" for >> AO UART. Drop the "amlogic,meson-uart" compatible string from the EE >> domain UART controllers. > > KernelCI detected that this patch introduced a regression in > stable-rc/linux-4.14.y (4.14.267) on a meson8b-odroidc1. > After this patch was applied the tests running on this platform don't > show any serial output. > > This doesn't happen in other stable branches nor in mainline, but 4.14 > hasn't still reached EOL and it'd be good to find a fix. > > Here's the bisection report: > https://groups.io/g/kernelci-results/message/40147 > > KernelCI info: > https://linux.kernelci.org/test/case/id/64234f7761021a30b262f776/ > > Test log: > https://storage.kernelci.org/stable-rc/linux-4.14.y/v4.14.311-43-g88e481d604e9/arm/multi_v7_defconfig/gcc-10/lab-baylibre/baseline-meson8b-odroidc1.html Lo! From the earlier discussion[1] it seems the mainline developers of the patch-set don't care (which is fine). And the stable team always has a lot of work at hand, which might explain why they haven't looked into this. Hence let me try to fill this gap a little here by asking: Have you tried if reverting the change on top of the latest 4.14.y kernel works and looks safe (e.g. doesn't cause a regression on its own)? I also briefly looked into "git log v4.14..v4.19 -- arch/arm/boot/dts/meson.dtsi" and noticed commit 291f45dd6da ("ARM: dts: meson: fixing USB support on Meson6, Meson8 and Meson8b") [v4.15-rc1] that mentions a fix for the Odroid-C1+ board -- which afaics wasn't backported to 4.14.y. Is that maybe why this happens on 4.14.y and not on 4.19.y? Note though: It's just a wild guess from the peanut gallery, as this is not my area of expertise! Ciao, Thorsten [1] https://lore.kernel.org/lkml/20230405132900.ci35xji3xbb3igar@rcn-XPS-13-9305/ Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page. #regzbot poke
