From: Flavio Leitner <fbl@redhat•com>
To: Flavio Leitner <fbl@redhat•com>
Cc: Stephen Boyd <sboyd@codeaurora•org>,
mjr@cs•wisc.edu, davem@davemloft•net, ben@simtec•co.uk,
netdev@vger•kernel.org
Subject: Re: [PATCH] ks8851: Fix missing mutex_lock/unlock
Date: Thu, 12 Apr 2012 18:19:40 -0300 [thread overview]
Message-ID: <20120412181940.7140ecb2@asterix.rh> (raw)
In-Reply-To: <20120412175945.1bbdd9bb@asterix.rh>
On Thu, 12 Apr 2012 17:59:45 -0300
Flavio Leitner <fbl@redhat•com> wrote:
> On Thu, 12 Apr 2012 13:34:32 -0700
> Stephen Boyd <sboyd@codeaurora•org> wrote:
>
> > On 04/12/12 13:06, mjr@cs•wisc.edu wrote:
> > > From: Matt Renzelmann <mjr@cs•wisc.edu>
> > >
> > > All calls to ks8851_rdreg* and ks8851_wrreg* should be protected with
> > > the driver's lock mutex. A spurious interrupt may otherwise cause a
> > > crash.
> > >
> > > Signed-off-by: Matt Renzelmann <mjr@cs•wisc.edu>
> > > ---
> > >
> > > Thank you, Mr. Leitner, for providing feedback. I agree with your
> > > changes and have updated the patch to reflect them. I apologize for
> > > missing the driver name in the title -- I've updated the patch with
> > > that information as well. Please let me know if there is anything
> > > else I should fix/change.
> > >
> > > drivers/net/ethernet/micrel/ks8851.c | 8 ++++++--
> > > 1 files changed, 6 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
> > > index c722aa6..20237dc 100644
> > > --- a/drivers/net/ethernet/micrel/ks8851.c
> > > +++ b/drivers/net/ethernet/micrel/ks8851.c
> > > @@ -1417,6 +1417,7 @@ static int __devinit ks8851_probe(struct spi_device *spi)
> > > {
> > > struct net_device *ndev;
> > > struct ks8851_net *ks;
> > > + int result;
> > > int ret;
> > >
> > > ndev = alloc_etherdev(sizeof(struct ks8851_net));
> > > @@ -1515,9 +1516,12 @@ static int __devinit ks8851_probe(struct spi_device *spi)
> > > goto err_netdev;
> > > }
> > >
> > > + mutex_lock(&ks->lock);
> > > + result = CIDER_REV_GET(ks8851_rdreg16(ks, KS_CIDER));
> > > + mutex_unlock(&ks->lock);
> > > +
> > > netdev_info(ndev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
> > > - CIDER_REV_GET(ks8851_rdreg16(ks, KS_CIDER)),
> > > - ndev->dev_addr, ndev->irq,
> > > + result, ndev->dev_addr, ndev->irq,
> > > ks->rc_ccr & CCR_EEPROM ? "has" : "no");
> > >
> > > return 0;
> >
> > This register is already read in the probe function and the lock is not
> > held there so you seem to have missed a couple. I would guess it doesn't
> > really matter tha we don't grab the lock though because the device isn't
> > actively sending/receiving packets. How about this instead?
>
> I believe that's because the IRQ isn't reserved yet, so there is no problem.
So, what about this instead:
diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index c722aa6..7137f47 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -1417,6 +1417,7 @@ static int __devinit ks8851_probe(struct spi_device *spi)
{
struct net_device *ndev;
struct ks8851_net *ks;
+ unsigned int cider;
int ret;
ndev = alloc_etherdev(sizeof(struct ks8851_net));
@@ -1485,7 +1486,8 @@ static int __devinit ks8851_probe(struct spi_device *spi)
/* simple check for a valid chip being connected to the bus */
- if ((ks8851_rdreg16(ks, KS_CIDER) & ~CIDER_REV_MASK) != CIDER_ID) {
+ cider = ks8851_rdreg16(ks, KS_CIDER);
+ if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
dev_err(&spi->dev, "failed to read device ID\n");
ret = -ENODEV;
goto err_id;
@@ -1516,7 +1518,7 @@ static int __devinit ks8851_probe(struct spi_device *spi)
}
netdev_info(ndev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
- CIDER_REV_GET(ks8851_rdreg16(ks, KS_CIDER)),
+ CIDER_REV_GET(cider),
ndev->dev_addr, ndev->irq,
ks->rc_ccr & CCR_EEPROM ? "has" : "no");
fbl
next prev parent reply other threads:[~2012-04-12 21:20 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-12 20:06 [PATCH] ks8851: Fix missing mutex_lock/unlock mjr
2012-04-12 20:34 ` Stephen Boyd
2012-04-12 20:56 ` Matt Renzelmann
2012-04-12 20:59 ` Flavio Leitner
2012-04-12 21:19 ` Flavio Leitner [this message]
2012-04-12 20:40 ` Flavio Leitner
-- strict thread matches above, loose matches on Subject: below --
2012-04-12 21:28 mjr
2012-04-12 22:03 ` Ben Hutchings
2012-04-12 23:15 mjr
2012-04-13 0:22 ` Flavio Leitner
2012-04-13 17:46 ` Stephen Boyd
2012-04-13 17:59 mjr
2012-04-13 18:05 ` David Miller
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