Re: [PATCH RESEND 1/2] arm: berlin: use non-self-cleared reset register to reset cpu

[Jisheng Zhang]

Dear Sebastian,

On Mon, 21 Sep 2015 10:18:25 +0800
Jisheng Zhang <jszhang@xxxxxxxxxxx> wrote:

> 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.

I found these two patches are missing in your round 1 berlin pull request. Do
you want me send v2 patches applying the above changes you suggested?

Thanks,
Jisheng

> 
> > 
> > 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);
> > >   }
> > >
> > 
> 

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