From: Francois Romieu <romieu@fr.zoreil.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mike Sinkovsky <msink@permonline.ru>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/2] Ethernet driver for the WIZnet W5100 chip
Date: Sat, 31 Mar 2012 11:40:14 +0200 [thread overview]
Message-ID: <20120331094014.GA7746@electric-eye.fr.zoreil.com> (raw)
In-Reply-To: <1333099431.19659.15.camel@edumazet-laptop>
Eric Dumazet <eric.dumazet@gmail.com> :
> Le vendredi 30 mars 2012 ?? 13:00 +0600, Mike Sinkovsky a ??crit :
> > Tested and used in production with Blackfin BF531 embedded processor.
[...]
> > +static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev)
> > +{
> > + struct w5100_priv *priv = netdev_priv(ndev);
> > + u16 offset;
> > +
> > + if (w5100_read16(priv, W5100_S0_TX_FSR) < skb->len) {
>
> There is a race here.
>
> Interrupt came come right here before you set the stop_queue()
>
>
> > + netif_stop_queue(ndev);
>
> So Here I suggest adding a test again
>
> if (w5100_read16(priv, W5100_S0_TX_FSR) >= skb->len)
> netif_wake_queue(ndev);
> else
> return NETDEV_TX_BUSY;
The start_tx logic seems broken anyway: it claims it always can take
packets until it is given one it can't process. The driver should rather
do the opposite and stop queueing as soon as there is no guarantee for
the next packet.
--
Ueimor
next prev parent reply other threads:[~2012-03-31 9:43 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-19 9:23 [PATCH v2] ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-03-20 18:08 ` Ben Hutchings
2012-03-21 14:49 ` Florian Fainelli
2012-03-22 6:58 ` Mike Sinkovsky
2012-03-24 11:02 ` [PATCH v3] Ethernet " Mike Sinkovsky
2012-03-24 15:53 ` Joe Perches
2012-03-24 16:10 ` Eric Dumazet
2012-03-26 9:05 ` Mike Sinkovsky
2012-03-26 9:07 ` [PATCH v4] " Mike Sinkovsky
2012-03-28 2:35 ` David Miller
2012-03-30 7:00 ` [PATCH v5 1/2] " Mike Sinkovsky
2012-03-31 21:45 ` Mark Brown
2012-03-30 7:00 ` [PATCH v5 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-03-30 9:23 ` Eric Dumazet
2012-03-31 9:40 ` Francois Romieu [this message]
2012-03-31 9:46 ` Francois Romieu
2012-03-31 9:52 ` Mike Sinkovsky
2012-03-31 10:24 ` Eric Dumazet
2012-03-31 21:23 ` Mark Brown
2012-04-02 9:40 ` Mike Sinkovsky
2012-04-02 11:21 ` Mark Brown
2012-04-03 10:58 ` [PATCH v6 0/2] Ethernet drivers for WIZnet chips Mike Sinkovsky
2012-04-03 11:39 ` Eric Dumazet
2012-04-03 12:15 ` Mike Sinkovsky
2012-04-03 12:29 ` Eric Dumazet
2012-04-04 5:58 ` Mike Sinkovsky
2012-04-04 6:17 ` Eric Dumazet
2012-04-04 7:25 ` Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 " Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 " Mike Sinkovsky
2012-04-05 1:15 ` David Miller
2012-04-05 5:36 ` Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 0/2] Ethernet drivers for WIZnet chips Mike Sinkovsky
2012-04-05 5:33 ` [PATCH v9 " Mike Sinkovsky
2012-04-05 5:47 ` David Miller
2012-04-05 5:33 ` [PATCH v9 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-05 5:33 ` [PATCH v9 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-03 10:58 ` [PATCH v6 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-03 13:36 ` Mark Brown
2012-04-04 6:18 ` Mike Sinkovsky
2012-04-04 10:01 ` Mark Brown
2012-04-04 11:00 ` Mike Sinkovsky
2012-04-03 10:58 ` [PATCH v6 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
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