[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@googl...
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-g88e481d604...
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