Re: Re: BCM5301x SMP

Sorry for not answering earlier.

I'll reorder the text in your message a little so that I can reply to the
more important bits first.

On Sat, Jun 28, 2025 at 04:49:05PM +0900, Mori Hiroki wrote:

> problem case.
> 
> [   4.5676083] WARNING: CHECK AND RESET THE DATE!
> init: fatal sign[  34.7399758] panic: kpsignal2(20)
> [  34.7399758] cpu0: Begin traceback...
> ...
> db{0}> ps 
> PID     LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
> 1         1 3   1       180           9fde9d00               init wait

Signal 20 is SIGCHLD.  Receiving this signal is normal.  And init(8)
ignores it.  It certainly doesn't print "fatal signal" for it.  Are you
sure this is the problem case?

> no problem case.
> 
> [   4.5775946] WARNING: CHECK AND RESET THE DATE!
> [   4.5999814] 1.1(init): trap: signo=10 code=2 addr=0x7fffeb58 trap=0x1c06
> [   4.5999814] r0=7fffeff0 r1=00000000 r2=00000000 r3=00000000
> [   4.6136304] r4=00000000 r5=00000000 r6=00000000 r7=00000000
> [   4.6136304] r8=00000000 r9=00000000 rA=00000000 rB=00000000
> [   4.6250933] ip=7fffeb58 sp=7fffeb58 lr=7bed0588 pc=7bed0588 spsr=00000010
> [   4.6320815] panic: kpsignal2(10)
> [   4.6320815] cpu0: Begin traceback...
> ...
> db{0}> ps
> PID     LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
> 1    >    1 7   0         0           9fde64c0               init

Signal 10 is SIGBUS.  That would be the real problem, IMHO.  googling for
'arm traps "0x1c06"' I found this:
https://linux-arm-kernel.infradead.narkive.com/OdBwOmnQ/patch-v4-0-4-arm-bcm5301x-initial-support-for-the-bcm5301x-bcm470x-socs-with-arm-cpu#post4
https://linux-arm-kernel.infradead.narkive.com/MWaNp4Pi/patch-v6-0-4-arm-bcm5301x-initial-support-for-the-bcm5301x-bcm470x-socs-with-arm-cpu#post4

Seems like "-current" Linux still contains an updated version of this
workaround:

https://github.com/torvalds/linux/blob/66701750d5565c574af42bef0b789ce0203e3071/arch/arm/mach-bcm/bcm_5301x.c#L22

> I add this code.

> BCM5301x is non FDT. Where I add cache opration?

I have no idea where you would need to add the cache operation in this
particular case.  I was hoping that maybe that particular change from 5
years ago might help you to identify the general area in your code.  If it
turns out to be a cache invalidation issue.  But I guess the point is moot.

--chris