[RFC] Question about contributing mt6577 support but SMP doesn't work

Boris Lysov arzamas-16 at mail.ee
Fri Jan 29 20:55:57 EST 2021


Hello! I'm working on bringing the initial support for mt6577 into
the mainline kernel. I've got the base set of hardware to work: timers,
and few interrupt controllers, and all 4 UARTs, and PL310 cache
controller. My test device boots mainline successfully and runs stable!

I'm having issues with getting SMP to work. mt6577 is a dual-core SoC,
and broken SMP means half of the processing power is unavailable. I
tried to use the existing SMP bring-up code located in
arch/arm/mach-mediatek/platsmp.c , but it didn't work albeit all
specified registers were correct. I also tried porting the SMP init
code from the downstream mediatek kernel, but it never worked either.

My question is: could I still contribute my device support patches
despite literally 50% of the CPU not working? I *strongly* doubt they
would be accepted because of it, but on the other hand devices with
mt6577 (and other compatible SoCs like mt8317) are still able to boot
and run bare mainline kernel on a single core. I ran out of ideas on
how to make that pesky 2nd core come up online with my poor knowledge.




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