[PATCH 3.18 026/145] ARM: 8584/1: floppy: avoid gcc-6 warning

From: Greg Kroah-Hartman
Date: Sun Apr 16 2017 - 06:52:23 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@xxxxxxxx>

commit dd665be0e243873343a28e18f9f345927b658daf upstream.

gcc-6.0 warns about comparisons between two identical expressions,
which is what we get in the floppy driver when writing to the FD_DOR
register:

drivers/block/floppy.c: In function 'set_dor':
drivers/block/floppy.c:810:44: error: self-comparison always evaluates to true [-Werror=tautological-compare]
fd_outb(newdor, FD_DOR);

It would be nice to use a static inline function instead of the
macro, to avoid the warning, but we cannot do that because the
FD_DOR definition is incomplete at this point.

Adding a cast to (u32) is a harmless way to shut up the warning,
just not very nice.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm/include/asm/floppy.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/include/asm/floppy.h
+++ b/arch/arm/include/asm/floppy.h
@@ -17,7 +17,7 @@

#define fd_outb(val,port) \
do { \
- if ((port) == FD_DOR) \
+ if ((port) == (u32)FD_DOR) \
fd_setdor((val)); \
else \
outb((val),(port)); \