Patchwork [20/21] ARM: 7347/1: SCU: use cpu_logical_map for per-CPU low power mode

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Submitter Ike Panhc
Date June 6, 2012, 12:29 p.m.
Message ID <1338985788-26627-1-git-send-email-ike.pan@canonical.com>
Download mbox | patch
Permalink /patch/163355/
State New
Headers show

Comments

Ike Panhc - June 6, 2012, 12:29 p.m.
From: Will Deacon <will.deacon@arm.com>

BugLink: http://launchpad.net/bugs/1008345

scu_power_mode changes the power mode for the current CPU, which it
determines from smp_processor_id(). However, this assumes that the
physical CPU number is equal to Linux's logical CPU number and if this
is not true, we will power off the wrong CPU.

This patch uses cpu_logical_map to translate the logical CPU number
into a physical one in scu_power_mode.

Reported-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
(cherry picked from commit 0bd82adee38046fcf180a60ca56c181702287646)

Signed-off-by: Ike Panhc <ike.pan@canonical.com>
---
 arch/arm/kernel/smp_scu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
index 8f5dd79..b9f015e 100644
--- a/arch/arm/kernel/smp_scu.c
+++ b/arch/arm/kernel/smp_scu.c
@@ -11,6 +11,7 @@ 
 #include <linux/init.h>
 #include <linux/io.h>
 
+#include <asm/smp_plat.h>
 #include <asm/smp_scu.h>
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
@@ -74,7 +75,7 @@  void scu_enable(void __iomem *scu_base)
 int scu_power_mode(void __iomem *scu_base, unsigned int mode)
 {
 	unsigned int val;
-	int cpu = smp_processor_id();
+	int cpu = cpu_logical_map(smp_processor_id());
 
 	if (mode > 3 || mode == 1 || cpu > 3)
 		return -EINVAL;