On Fri, Jul 22, 2022 at 01:00:32AM +0900, Vincent Mailhol wrote:
> 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@xxxxxxxxxx>
> Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
Heh, Marc just sent the same patch. Just in case this one gets picked up
instead:
Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Thanks for the quick response!
> ---
> 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 50f6719b3aa4..32804fed116c 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);
> @@ -502,7 +503,6 @@ 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
>
