netdev - Re: [PATCH] can: ti_hecc: fix close when napi poll is active

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Message-ID: <yw1xef7q63h2.fsf@mansr.com>
Date:   Fri, 01 Mar 2019 15:04:09 +0000
From:   Måns Rullgård <mans@...sr.com>
To:     Jeroen Hofstee <jhofstee@...tronenergy.com>
Cc:     linux-can@...r.kernel.org, Wolfgang Grandegger <wg@...ndegger.com>,
        Marc Kleine-Budde <mkl@...gutronix.de>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] can: ti_hecc: fix close when napi poll is active

Jeroen Hofstee <jhofstee@...tronenergy.com> writes:

> When closing this CAN interface while napi poll is active, for example with:
> `ip link set can0 down` several interfaces freeze. This seemed to be caused
> by napi_disable called from ti_hecc_close expecting the scheduled probe to
> either return quota or call napi_complete. Since the poll functions has a
> check for netif_running it returns 0 and doesn't call napi_complete and hence
> violates the napi its expectation.
>
> So remove this check, so either napi_complete is called or quota is returned.
>
> Signed-off-by: Jeroen Hofstee <jhofstee@...tronenergy.com>
> ---
>  drivers/net/can/ti_hecc.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
> index db6ea93..42813d3 100644
> --- a/drivers/net/can/ti_hecc.c
> +++ b/drivers/net/can/ti_hecc.c
> @@ -603,9 +603,6 @@ static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
>  	u32 mbx_mask;
>  	unsigned long pending_pkts, flags;
>
> -	if (!netif_running(ndev))
> -		return 0;
> -
>  	while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
>  		num_pkts < quota) {
>  		mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
> -- 
> 2.7.4

This seems to have been lost or forgotten.

-- 
Måns Rullgård