On Thu, 2016-30-06 at 14:34:37 UTC, Oliver O'Halloran wrote:

This patch adds an OPAL console backend to the powerpc boot wrapper so
that decompression failures inside the wrapper can be reported to the
user. This is important since it typically indicates data corruption in
the firmware and other nasty things.

...

Cc: stable@vger.kernel.org

I've dropped stable, something this big needs to get some wider testing before
it goes to stable.

It was also giving me:

  arch/powerpc/boot/opal.c:30:12: warning: ���opal_con_open��� defined but not used [-Wunused-function]

So I applied the following patch to fix it:

diff --git a/arch/powerpc/boot/opal.c b/arch/powerpc/boot/opal.c
index 3a2ce1e1f048..1f37e1c1d6d8 100644
--- a/arch/powerpc/boot/opal.c
+++ b/arch/powerpc/boot/opal.c

@@ -13,6 +13,8 @@
 #include <libfdt.h>
 #include "../include/asm/opal-api.h"
 
+#ifdef __powerpc64__
+
 /* Global OPAL struct used by opal-call.S */
 struct opal {
 	u64 base;

@@ -70,7 +72,6 @@ static void opal_init(void)
 	opal.entry = be64_to_cpu(opal.entry);
 }
 
-#ifdef __powerpc64__
 int opal_console_init(void *devp, struct serial_console_data *scdp)
 {
 	opal_init();

@@ -94,4 +95,4 @@ int opal_console_init(void *devp, struct serial_console_data *scdp)
 {
 	return -1;
 }
-#endif
+#endif /* __powerpc64__ */

cheers