gcc-7 reports a warning that earlier versions did not have:
drivers/net/ethernet/rocker/rocker_ofdpa.c: In function 'ofdpa_port_stp_update':
arch/x86/include/asm/string_32.h:79:22: error: '*((void *)&prev_ctrls+4)' may
be used uninitialized in this function [-Werror=maybe-uninitialized]
*((short *)to + 2) = *((short *)from + 2);
~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/rocker/rocker_ofdpa.c:2218:7: note: '*((void
*)&prev_ctrls+4)' was declared here
This is clearly a variation of the warning about 'prev_state' that
was shut up using uninitialized_var().
We can slightly simplify the code and get rid of the warning by unconditionally
saving the prev_state and prev_ctrls variables. The inlined memcpy is not
particularly expensive here, as it just has to read five bytes from one or
two cache lines.
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
drivers/net/ethernet/rocker/rocker_ofdpa.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/rocker/rocker_ofdpa.c
b/drivers/net/ethernet/rocker/rocker_ofdpa.c
index 7cd76b6b5cb9..2ae852454780 100644
--- a/drivers/net/ethernet/rocker/rocker_ofdpa.c
+++ b/drivers/net/ethernet/rocker/rocker_ofdpa.c
@@ -2216,18 +2216,15 @@ static int ofdpa_port_stp_update(struct ofdpa_port
*ofdpa_port,
{
bool want[OFDPA_CTRL_MAX] = { 0, };
bool prev_ctrls[OFDPA_CTRL_MAX];
- u8 uninitialized_var(prev_state);
+ u8 prev_state;
int err;
int i;
- if (switchdev_trans_ph_prepare(trans)) {
- memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls));
- prev_state = ofdpa_port->stp_state;
- }
-
- if (ofdpa_port->stp_state == state)
+ prev_state = ofdpa_port->stp_state;
+ if (prev_state == state)
return 0;
+ memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls));
ofdpa_port->stp_state = state;
switch (state) {
--
2.9.0
