From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Bizon Subject: Re: [PATCH] bcm63xx_enet: timeout off by one in do_mdio_op() Date: Wed, 30 Sep 2009 16:01:28 +0200 Message-ID: <1254319288.1627.758.camel@sakura.staff.proxad.net> References: <4AB7DD50.6030409@gmail.com> Reply-To: mbizon@freebox.fr Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Andrew Morton To: Roel Kluin Return-path: Received: from smtp6-g21.free.fr ([212.27.42.6]:43274 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752299AbZI3OBd (ORCPT ); Wed, 30 Sep 2009 10:01:33 -0400 In-Reply-To: <4AB7DD50.6030409@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2009-09-21 at 22:08 +0200, Roel Kluin wrote: Hi Roel, > `while (limit-- >= 0)' reaches -2 after the loop upon timeout. The 1000us limit was chosen arbitrarily, since mdio access are much shorter, and was just to prevent CPU lockup in case of hardware bug. But it looks like a bug, and since you're the second one reporting this, this should be fixed :) > Signed-off-by: Roel Kluin Acked-by: Maxime Bizon > --- > Small chance to occur, probably. > > diff --git a/drivers/net/bcm63xx_enet.c b/drivers/net/bcm63xx_enet.c > index 09d2709..ba29dc3 100644 > --- a/drivers/net/bcm63xx_enet.c > +++ b/drivers/net/bcm63xx_enet.c > @@ -90,7 +90,7 @@ static int do_mdio_op(struct bcm_enet_priv *priv, unsigned int data) > if (enet_readl(priv, ENET_IR_REG) & ENET_IR_MII) > break; > udelay(1); > - } while (limit-- >= 0); > + } while (limit-- > 0); > > return (limit < 0) ? 1 : 0; > } -- Maxime