From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751810AbZL2NtI (ORCPT ); Tue, 29 Dec 2009 08:49:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751630AbZL2NtH (ORCPT ); Tue, 29 Dec 2009 08:49:07 -0500 Received: from lan.nucleusys.com ([78.83.248.164]:44996 "EHLO zztop.nucleusys.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751612AbZL2NtG (ORCPT ); Tue, 29 Dec 2009 08:49:06 -0500 X-Greylist: delayed 2124 seconds by postgrey-1.27 at vger.kernel.org; Tue, 29 Dec 2009 08:49:05 EST Date: Tue, 29 Dec 2009 15:13:28 +0200 (EET) From: Petko Manolov To: Roel Kluin cc: Petko Manolov , linux-usb@vger.kernel.org, netdev@vger.kernel.org, Andrew Morton , LKML Subject: Re: [PATCH] usbnet: test off by one In-Reply-To: <4B37D000.6070009@gmail.com> Message-ID: References: <4B37D000.6070009@gmail.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Roel, MII_TIMEOUT is a number i made up myself, reasonably small so the driver won't sit there forever, but higher than 2. While testing the gadget i discovered that reading MII registers sometimes require more than one attempt. Technically you're right. In practice it doesn't matter much. Hitting the boundary condition mean things are already out of hand. Petko On Sun, 27 Dec 2009, Roel Kluin wrote: > With `while (i++ < MII_TIMEOUT)' i reaches MII_TIMEOUT + 1 after the loop > This is probably unlikely a problem in practice. > > Signed-off-by: Roel Kluin > --- > drivers/net/usb/rtl8150.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c > index f14d225..fd19db0 100644 > --- a/drivers/net/usb/rtl8150.c > +++ b/drivers/net/usb/rtl8150.c > @@ -270,7 +270,7 @@ static int read_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 * reg) > get_registers(dev, PHYCNT, 1, data); > } while ((data[0] & PHY_GO) && (i++ < MII_TIMEOUT)); > > - if (i < MII_TIMEOUT) { > + if (i <= MII_TIMEOUT) { > get_registers(dev, PHYDAT, 2, data); > *reg = data[0] | (data[1] << 8); > return 0; > @@ -295,7 +295,7 @@ static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg) > get_registers(dev, PHYCNT, 1, data); > } while ((data[0] & PHY_GO) && (i++ < MII_TIMEOUT)); > > - if (i < MII_TIMEOUT) > + if (i <= MII_TIMEOUT) > return 0; > else > return 1; >