Re: [PATCH RESEND 1/2] arm: berlin: use non-self-cleared reset register to reset cpu
From: Jisheng Zhang
Date: Sun Sep 20 2015 - 22:22:30 EST
Dear Sebastian,
On Sun, 20 Sep 2015 20:04:01 +0200
Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> wrote:
> On 14.09.2015 08:47, Jisheng Zhang wrote:
> > In Berlin SoCs, there are two kinds of cpu reset control registers: the
> > first one's corresponding bits will be self-cleared after some cycles,
> > while the second one's bits won't. Previously the first kind of reset
> > control register is used, this patch uses the second kind one to prepare
> > for the next hotplug commit.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> > ---
> > arch/arm/mach-berlin/platsmp.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/mach-berlin/platsmp.c b/arch/arm/mach-berlin/platsmp.c
> > index 34a3753..bde327b 100644
> > --- a/arch/arm/mach-berlin/platsmp.c
> > +++ b/arch/arm/mach-berlin/platsmp.c
> > @@ -17,7 +17,7 @@
> > #include <asm/smp_plat.h>
> > #include <asm/smp_scu.h>
> >
> > -#define CPU_RESET 0x00
> > +#define CPU_RESET 0x20
>
> Jisheng,
>
> I am fine with the patch itself, except that I'd like to rather
> rename the 0x00-register to CPU_RESET_SC with a comment about
> the self-clearing nature. The 0x20-register would then be named
> CPU_RESET_NON_SC and used the way you propose.
Good idea. And such comment would let people understand why do we change
as that.
>
> Are you fine with me naming the registers accordingly while
> applying the patches?
Sure, I'm fine. Thank you very much.
>
> Sebastian
>
> > #define RESET_VECT 0x00
> > #define SW_RESET_ADDR 0x94
> > @@ -31,6 +31,8 @@ static inline void berlin_perform_reset_cpu(unsigned int cpu)
> > u32 val;
> >
> > val = readl(cpu_ctrl + CPU_RESET);
> > + val &= ~BIT(cpu_logical_map(cpu));
> > + writel(val, cpu_ctrl + CPU_RESET);
> > val |= BIT(cpu_logical_map(cpu));
> > writel(val, cpu_ctrl + CPU_RESET);
> > }
> >
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/