Building with -O3 introduces a false-positive warning in this file:
In file included from include/linux/compiler_types.h:68,
from <command-line>:
drivers/input/mouse/appletouch.c: In function 'atp_complete_geyser_3_4':
include/linux/compiler-gcc.h:71:45: error: 'x_z' may be used uninitialized in this function [-Werror=maybe-uninitialized]
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
^~~~~~~~~~~~
drivers/input/mouse/appletouch.c:657:12: note: 'x_z' was declared here
int x, y, x_z, y_z, x_f, y_f;
^~~
In file included from include/linux/compiler_types.h:68,
from <command-line>:
drivers/input/mouse/appletouch.c: In function 'atp_complete_geyser_1_2':
include/linux/compiler-gcc.h:71:45: error: 'x_z' may be used uninitialized in this function [-Werror=maybe-uninitialized]
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
^~~~~~~~~~~~
drivers/input/mouse/appletouch.c:517:12: note: 'x_z' was declared here
int x, y, x_z, y_z, x_f, y_f;
^~~
The variables are not actually used here since the only usage
happens when both 'x' and 'y' are non-zero, but this is something
that gcc fails to track.
Fixes: mmtom ("init/Kconfig: enable -O3 for all arches")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/input/mouse/appletouch.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c
index 3f06e8a495d8..ec2139c43fcd 100644
--- a/drivers/input/mouse/appletouch.c
+++ b/drivers/input/mouse/appletouch.c
@@ -330,7 +330,7 @@ static void atp_reinit(struct work_struct *work)
retval);
}
-static int atp_calculate_abs(struct atp *dev, int offset, int nb_sensors,
+static noinline int atp_calculate_abs(struct atp *dev, int offset, int nb_sensors,
int fact, int *z, int *fingers)
{
int i, pass;
--
2.20.0
