linux-kernel - [PATCH] arm: zynq: hotplug: Remove unreachable code

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Date:	Thu,  1 Aug 2013 09:36:53 -0700
From:	Soren Brinkmann <soren.brinkmann@...inx.com>
To:	Michal Simek <michal.simek@...inx.com>,
	Russell King <linux@....linux.org.uk>
Cc:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	Soren Brinkmann <soren.brinkmann@...inx.com>
Subject: [PATCH] arm: zynq: hotplug: Remove unreachable code

zynq_platform_do_lowpower() does never return. Hence remove
all code which relies on that function returning and consolidate the
remains.

Signed-off-by: Soren Brinkmann <soren.brinkmann@...inx.com>
---
 arch/arm/mach-zynq/hotplug.c | 55 ++++----------------------------------------
 1 file changed, 5 insertions(+), 50 deletions(-)

diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c
index c89672b..5052c70 100644
--- a/arch/arm/mach-zynq/hotplug.c
+++ b/arch/arm/mach-zynq/hotplug.c
@@ -40,44 +40,6 @@ static inline void zynq_cpu_enter_lowpower(void)
 	  : "cc");
 }
 
-static inline void zynq_cpu_leave_lowpower(void)
-{
-	unsigned int v;
-
-	asm volatile(
-	"	mrc	p15, 0, %0, c1, c0, 0\n"
-	"	orr	%0, %0, %1\n"
-	"	mcr	p15, 0, %0, c1, c0, 0\n"
-	"	mrc	p15, 0, %0, c1, c0, 1\n"
-	"	orr	%0, %0, #0x40\n"
-	"	mcr	p15, 0, %0, c1, c0, 1\n"
-	  : "=&r" (v)
-	  : "Ir" (CR_C)
-	  : "cc");
-}
-
-static inline void zynq_platform_do_lowpower(unsigned int cpu, int *spurious)
-{
-	/*
-	 * there is no power-control hardware on this platform, so all
-	 * we can do is put the core into WFI; this is safe as the calling
-	 * code will have already disabled interrupts
-	 */
-	for (;;) {
-		dsb();
-		wfi();
-
-		/*
-		 * Getting here, means that we have come out of WFI without
-		 * having been woken up - this shouldn't happen
-		 *
-		 * Just note it happening - when we're woken, we can report
-		 * its occurrence.
-		 */
-		(*spurious)++;
-	}
-}
-
 /*
  * platform-specific code to shutdown a CPU
  *
@@ -85,20 +47,13 @@ static inline void zynq_platform_do_lowpower(unsigned int cpu, int *spurious)
  */
 void zynq_platform_cpu_die(unsigned int cpu)
 {
-	int spurious = 0;
-
-	/*
-	 * we're ready for shutdown now, so do it
-	 */
 	zynq_cpu_enter_lowpower();
-	zynq_platform_do_lowpower(cpu, &spurious);
 
 	/*
-	 * bring this CPU back into the world of cache
-	 * coherency, and then restore interrupts
+	 * there is no power-control hardware on this platform, so all
+	 * we can do is put the core into WFI; this is safe as the calling
+	 * code will have already disabled interrupts
 	 */
-	zynq_cpu_leave_lowpower();
-
-	if (spurious)
-		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+	for (;;)
+		cpu_do_idle();
 }
-- 
1.8.3.4

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