[PATCH] powerpc/time: clear LPCR.LD when unneeded

[PATCH] powerpc/time: clear LPCR.LD when unneeded

[Oliver O'Halloran]

Currently the kernel will enable LD mode at boot when required. However,
when using kexec the second kernel may not want to have the LD enabled.
This patch ensures the second kernel will explicitly clear the LD flag
when not required by the current kernel.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
 arch/powerpc/kernel/time.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index be9751f1cb2a..816700e8a475 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -925,18 +925,16 @@ static void register_decrementer_clockevent(int cpu)
 
 static void enable_large_decrementer(void)
 {
-	if (!cpu_has_feature(CPU_FTR_ARCH_300))
-		return;
-
-	if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
-		return;
-
 	/*
 	 * If we're running as the hypervisor we need to enable the LD manually
 	 * otherwise firmware should have done it for us.
 	 */
-	if (cpu_has_feature(CPU_FTR_HVMODE))
+	if (decrementer_max > DECREMENTER_DEFAULT_MAX
+	    && cpu_has_feature(CPU_FTR_HVMODE)
+	    && cpu_has_feature(CPU_FTR_ARCH_300))
 		mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
+	else
+		mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_LD);
 }
 
 static void __init set_decrementer_max(void)
-- 
2.7.4