From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roel Kluin Subject: [PATCH v3] net: more timeouts that reach -1 Date: Fri, 27 Feb 2009 17:43:06 +0100 Message-ID: <49A8181A.5030106@gmail.com> References: <49A5286D.80304@gmail.com> <20090227114015.M80857@cooldavid.org> <25e057c00902270737x529fb5b8m2fdbb044fa75ab0d@mail.gmail.com> <20090227154440.M53654@cooldavid.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , netdev@vger.kernel.org, Andrew Morton To: cooldavid@cooldavid.org Return-path: Received: from an-out-0708.google.com ([209.85.132.243]:55365 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755126AbZB0QnJ (ORCPT ); Fri, 27 Feb 2009 11:43:09 -0500 Received: by an-out-0708.google.com with SMTP id c2so925145anc.1 for ; Fri, 27 Feb 2009 08:43:06 -0800 (PST) In-Reply-To: <20090227154440.M53654@cooldavid.org> Sender: netdev-owner@vger.kernel.org List-ID: Guo-Fu Tseng wrote: > On Fri, 27 Feb 2009 16:37:30 +0100, roel kluin wrote >> On Fri, Feb 27, 2009 at 12:43 PM, Guo-Fu Tseng wrote: >>> There should be no difference after this modification. >>> The return value of this function is: "limit > 0 ? limit : 0;" >> There is: >> In the last iteration limit is 1 during the test before it is decremented to 0. >> >> rxdesc = rxring->desc; >> rxdesc += i; >> >> If then we break out of the loop by the 'goto out;', we continue with: >> >> out: >> atomic_set(&rxring->next_to_clean, i); >> >> out_inc: >> atomic_inc(&jme->rx_cleaning); >> >> but since limit is already decremented, 0 is returned. >> >>> Guo-Fu Tseng >>> >> Roel > I see. > But the correct patch should be following one, right? > > =================================================================== > --- jme.c (revision 580) > +++ jme.c (working copy) > @@ -958,13 +958,14 @@ > goto out_inc; > > i = atomic_read(&rxring->next_to_clean); > - while (limit-- > 0) { > + while (limit > 0) { > rxdesc = rxring->desc; > rxdesc += i; > > if ((rxdesc->descwb.flags & RXWBFLAG_OWN) || > !(rxdesc->descwb.desccnt & RXWBDCNT_WBCPL)) > goto out; > + --limit; > > desccnt = rxdesc->descwb.desccnt & RXWBDCNT_DCNT; > > > > > Guo-Fu Tseng Correct, thanks. Here are all three patches again with another issue I spotted in drivers/net/ucc_geth_mii.c: After my patch it still wouldn't err, because timeout was unsigned. ------------------------------>8-------------8<--------------------------------- with while (timeout-- > 0); timeout reaches -1 after the loop, so the tests below are off by one. also don't do an '< 0' test on an unsigned. Signed-off-by: Roel Kluin --- diff --git a/drivers/net/arm/ks8695net.c b/drivers/net/arm/ks8695net.c index 1cf2f94..f3a1274 100644 --- a/drivers/net/arm/ks8695net.c +++ b/drivers/net/arm/ks8695net.c @@ -560,7 +560,7 @@ ks8695_reset(struct ks8695_priv *ksp) msleep(1); } - if (reset_timeout == 0) { + if (reset_timeout < 0) { dev_crit(ksp->dev, "Timeout waiting for DMA engines to reset\n"); /* And blithely carry on */ diff --git a/drivers/net/jme.c b/drivers/net/jme.c index 08b3405..a6e1a35 100644 --- a/drivers/net/jme.c +++ b/drivers/net/jme.c @@ -957,13 +957,14 @@ jme_process_receive(struct jme_adapter *jme, int limit) goto out_inc; i = atomic_read(&rxring->next_to_clean); - while (limit-- > 0) { + while (limit > 0) { rxdesc = rxring->desc; rxdesc += i; if ((rxdesc->descwb.flags & cpu_to_le16(RXWBFLAG_OWN)) || !(rxdesc->descwb.desccnt & RXWBDCNT_WBCPL)) goto out; + --limit; desccnt = rxdesc->descwb.desccnt & RXWBDCNT_DCNT; diff --git a/drivers/net/ucc_geth_mii.c b/drivers/net/ucc_geth_mii.c index 5463591..0ada4ed 100644 --- a/drivers/net/ucc_geth_mii.c +++ b/drivers/net/ucc_geth_mii.c @@ -107,7 +107,7 @@ int uec_mdio_read(struct mii_bus *bus, int mii_id, int regnum) static int uec_mdio_reset(struct mii_bus *bus) { struct ucc_mii_mng __iomem *regs = (void __iomem *)bus->priv; - unsigned int timeout = PHY_INIT_TIMEOUT; + int timeout = PHY_INIT_TIMEOUT; mutex_lock(&bus->mdio_lock); @@ -123,7 +123,7 @@ static int uec_mdio_reset(struct mii_bus *bus) mutex_unlock(&bus->mdio_lock); - if (timeout <= 0) { + if (timeout < 0) { printk(KERN_ERR "%s: The MII Bus is stuck!\n", bus->name); return -EBUSY; }