1 files changed, 24 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/cpu_setup_44x.S b/arch/powerpc/kernel/cpu_setup_44x.S
index c790634d946b..8e1812e2f3ee 100644
--- a/arch/powerpc/kernel/cpu_setup_44x.S
+++ b/arch/powerpc/kernel/cpu_setup_44x.S
@@ -20,7 +20,14 @@
 _GLOBAL(__setup_cpu_440ep)
         b       __init_fpu_44x
 _GLOBAL(__setup_cpu_440epx)
-        b       __init_fpu_44x
+        mflr    r4
+        bl      __init_fpu_44x
+        bl      __plb_disable_wrp
+        mtlr    r4
+        blr
+_GLOBAL(__setup_cpu_440grx)
+        b       __plb_disable_wrp
+
 
 /* enable APU between CPU and FPU */
 _GLOBAL(__init_fpu_44x)
@@ -31,3 +38,19 @@ _GLOBAL(__init_fpu_44x)
         isync
         blr
 
+/*
+ * Workaround for the incorrect write to DDR SDRAM errata.
+ * The write address can be corrupted during writes to
+ * DDR SDRAM when write pipelining is enabled on PLB0.
+ * Disable write pipelining here.
+ */
+#define DCRN_PLB4A0_ACR 0x81
+
+_GLOBAL(__plb_disable_wrp)
+        mfdcr   r3,DCRN_PLB4A0_ACR
+        /* clear WRP bit in PLB4A0_ACR */
+        rlwinm  r3,r3,0,8,6
+        mtdcr   DCRN_PLB4A0_ACR,r3
+        isync
+        blr
+