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

From: Sebastian Hesselbarth
Date: Sun Sep 20 2015 - 14:04:43 EST


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.

Are you fine with me naming the registers accordingly while
applying the patches?

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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