[PATCH 4.9 016/117] powerpc/powernv/smp: Fix spurious DBG() warning

[Greg Kroah-Hartman]

From: Oliver O'Halloran <oohall@xxxxxxxxx>

[ Upstream commit f6bac19cf65c5be21d14a0c9684c8f560f2096dd ]

When building with W=1 we get the following warning:

 arch/powerpc/platforms/powernv/smp.c: In function ‘pnv_smp_cpu_kill_self’:
 arch/powerpc/platforms/powernv/smp.c:276:16: error: suggest braces around
 	empty body in an ‘if’ statement [-Werror=empty-body]
   276 |      cpu, srr1);
       |                ^
 cc1: all warnings being treated as errors

The full context is this block:

 if (srr1 && !generic_check_cpu_restart(cpu))
 	DBG("CPU%d Unexpected exit while offline srr1=%lx!\n",
 			cpu, srr1);

When building with DEBUG undefined DBG() expands to nothing and GCC emits
the warning due to the lack of braces around an empty statement.

Signed-off-by: Oliver O'Halloran <oohall@xxxxxxxxx>
Reviewed-by: Joel Stanley <joel@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200804005410.146094-2-oohall@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/powerpc/platforms/powernv/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index eec0e8d0454d1..7e0f5fa0452b3 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -41,7 +41,7 @@
 #include <asm/udbg.h>
 #define DBG(fmt...) udbg_printf(fmt)
 #else
-#define DBG(fmt...)
+#define DBG(fmt...) do { } while (0)
 #endif
 
 static void pnv_smp_setup_cpu(int cpu)
-- 
2.27.0