Subject: Re: [PATCH] powerpc/boot: Copy serial.c in Makefile

From: Daniel Axtens <[email-masked]>
Date: Thu, 29 Nov 2018 15:45:46 +1100

Right, so as both 0-day and snowpatch tell me, this patch is wrong.

It turns out that this:
>  $(obj)/serial.c: $(obj)/autoconf.h
> +	$(Q)cp $< $@
is identical to:
cp arch/powerpc/boot/autoconf.h arch/powerpc/boot/serial.c

(Clearly my make mastery is inadequate.)

Amusingly this which works for my 64e uImage but obviously not for
anything that actually needs code from serial.c.

Further analysis suggests that making with -j1 triggers the issue, but
everything works with -j2 and above. That would make sense with the
timeline of when I discovered the issue because I changed my build
script to not build in parallel.

Regards,
Daniel