[U-Boot] [PATCH v2 1/3] Revert "arm: Replace v7_maint_dcache_all(ARMV7_DCACHE_CLEAN_INVAL_ALL) with asm code"

[Sandy Patterson]

I see the problem with 4.7-rc6. Is there a different kernel I should test
with?

On Fri, Jul 22, 2016 at 4:39 PM, Tom Rini <trini at konsulko.com> wrote:

> On Fri, Jul 22, 2016 at 10:40:11AM -0400, Sandy Patterson wrote:
>
> > Commit c09d29057a and df120142f36 break kernel loading on rock2 board.
> >
> > console output:
> > Starting kernel ...
> >
> > ### ERROR ### Please RESET the board ###
> >
> > This reverts commit c09d29057ab0b04db0857d319c6bff74de31b9c3.
> >
> > Conflicts:
> >       arch/arm/cpu/armv7/cache_v7.c
> >       arch/arm/cpu/armv7/cache_v7_asm.S
> >
> > Signed-off-by: Sandy Patterson <apatterson at sightlogix.com>
>
> So, we cannot do this.  The problem is two-fold.  First, newer GCCs will
> cause failure to boot with the way the code was, which is how we found
> this problem.  The second is that after some offline conversations with
> ARM Ltd people (and some other smart folks too, these operations cannot
> safely be done in C, there's just no way.  So we borrowed what the
> kernel does.  You need to figure out what behavior the (old?) kernel is
> relying on and either emulate that with a flag (like sunxi does, or at
> least did, at one point for some other issues of correct behavior vs
> existing kernels) or just not support those older kernels.
>
> --
> Tom
>