diff mbox series

can: pch_can: initialize errc before using it

Message ID 20220721160032.9348-1-mailhol.vincent@wanadoo.fr (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series can: pch_can: initialize errc before using it | expand

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Context Check Description
netdev/tree_selection success Series ignored based on subject

Commit Message

Vincent Mailhol July 21, 2022, 4 p.m. UTC
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>
---
 drivers/net/can/pch_can.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Nathan Chancellor July 21, 2022, 4:02 p.m. UTC | #1
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@kernel.org>
> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Heh, Marc just sent the same patch. Just in case this one gets picked up
instead:

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

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
>
diff mbox series

Patch

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;