[PATCH 5.4 140/389] can: pch_can: pch_can_error(): initialize errc before using it

Greg Kroah-Hartman
2022-08-23T11:25:09Z

From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

[ Upstream commit 9950f11211331180269867aef848c7cf56861742 ]

After commit 3a5c7e4611dd, the variable errc is accessed before being
initialized, c.f. below W=2 warning:

| In function 'pch_can_error',
| inlined from 'pch_can_poll' at drivers/net/can/pch_can.c:739:4:
| drivers/net/can/pch_can.c:501:29: warning: 'errc' may be used uninitialized [-Wmaybe-uninitialized]
| 501 | cf->data[6] = errc & PCH_TEC;
| | ^
| drivers/net/can/pch_can.c: In function 'pch_can_poll':
| drivers/net/can/pch_can.c:484:13: note: 'errc' was declared here
| 484 | u32 errc, lec;
| | ^~~~

Moving errc initialization up solves this issue.

Fixes: 3a5c7e4611dd ("can: pch_can: do not report txerr and rxerr during bus-off")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/all/20220721160032.9348-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/can/pch_can.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index b148572e4a74..586bda050d28 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -489,6 +489,7 @@ static void pch_can_error(struct net_device *ndev, u32 status)
if (!skb)
return;

+ errc = ioread32(&priv->regs->errc);
if (status & PCH_BUS_OFF) {
pch_can_set_tx_all(priv, 0);
pch_can_set_rx_all(priv, 0);
@@ -501,7 +502,6 @@ static void pch_can_error(struct net_device *ndev, u32 status)
cf->data[7] = (errc & PCH_REC) >> 8;
}

- errc = ioread32(&priv->regs->errc);
/* Warning interrupt. */
if (status & PCH_EWARN) {
state = CAN_STATE_ERROR_WARNING;
--
2.35.1