netdev - RE: [PATCH] net: fec: only clear a queue's work bit if the queue was emptied

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <VI1PR0401MB1855C25037E3E730B678B6EBFF7B0@VI1PR0401MB1855.eurprd04.prod.outlook.com>
Date:	Wed, 4 May 2016 02:12:23 +0000
From:	Fugang Duan <fugang.duan@....com>
To:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	"David S . Miller" <davem@...emloft.net>
CC:	"kernel@...gutronix.de" <kernel@...gutronix.de>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: RE: [PATCH] net: fec: only clear a queue's work bit if the queue was
 emptied

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de> Sent: Tuesday, May 03, 2016 10:39 PM
> To: Fugang Duan <fugang.duan@....com>; David S . Miller
> <davem@...emloft.net>
> Cc: kernel@...gutronix.de; netdev@...r.kernel.org
> Subject: [PATCH] net: fec: only clear a queue's work bit if the queue was
> emptied
> 
> In the receive path a queue's work bit was cleared unconditionally even if
> fec_enet_rx_queue only read out a part of the available packets from the
> hardware. This resulted in not reading any packets in the next napi turn and so
> packets were delayed or lost.
> 
> The obvious fix is to only clear a queue's bit when the queue was emptied.
> 
> Fixes: 4d494cdc92b3 ("net: fec: change data structure to support multiqueue")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
> ---
> Hello,
> 
> I created this patch against net/master. If you think it's to late to get it into 4.6
> and it doesn't fit on net-next/master, just tell me and I will rebase.
> 
> Best regards
> Uwe
> 
> 
>  drivers/net/ethernet/freescale/fec_main.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 08243c2ff4b4..2a03857cca18 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1521,9 +1521,15 @@ fec_enet_rx(struct net_device *ndev, int budget)
>  	struct fec_enet_private *fep = netdev_priv(ndev);
> 
>  	for_each_set_bit(queue_id, &fep->work_rx, FEC_ENET_MAX_RX_QS) {
> -		clear_bit(queue_id, &fep->work_rx);
> -		pkt_received += fec_enet_rx_queue(ndev,
> +		int ret;
> +
> +		ret = fec_enet_rx_queue(ndev,
>  					budget - pkt_received, queue_id);
> +
> +		if (ret < budget - pkt_received)
> +			clear_bit(queue_id, &fep->work_rx);
> +
> +		pkt_received += ret;
>  	}
>  	return pkt_received;
>  }
> --
> 2.8.0.rc3

Tested-by: Fugang Duan <fugang.duan@....com>
Acked-by: Fugang Duan <fugang.duan@....com>