[PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[Weiwei Wang]

Netpoll will call the interrupt handler with interrupts
disabled when using kgdboe, so spin_lock_irqsave() should
be used instead of spin_lock_irq() to prevent interrupts
from being incorrectly enabled.

Signed-off-by: Weiwei Wang <weiwei.wang@windriver.com>
---
 drivers/net/sb1250-mac.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/sb1250-mac.c b/drivers/net/sb1250-mac.c
index fe41e4e..ce10cfa 100644
--- a/drivers/net/sb1250-mac.c
+++ b/drivers/net/sb1250-mac.c
@@ -2069,9 +2069,10 @@ static irqreturn_t sbmac_intr(int irq,void *dev_instance)
 static int sbmac_start_tx(struct sk_buff *skb, struct net_device *dev)
 {
 	struct sbmac_softc *sc = netdev_priv(dev);
+	unsigned long flags;
 
 	/* lock eth irq */
-	spin_lock_irq (&sc->sbm_lock);
+	spin_lock_irqsave(&sc->sbm_lock, flags);
 
 	/*
 	 * Put the buffer on the transmit ring.  If we
@@ -2081,14 +2082,14 @@ static int sbmac_start_tx(struct sk_buff *skb, struct net_device *dev)
 	if (sbdma_add_txbuffer(&(sc->sbm_txdma),skb)) {
 		/* XXX save skb that we could not send */
 		netif_stop_queue(dev);
-		spin_unlock_irq(&sc->sbm_lock);
+		spin_unlock_irqrestore(&sc->sbm_lock, flags);
 
 		return 1;
 	}
 
 	dev->trans_start = jiffies;
 
-	spin_unlock_irq (&sc->sbm_lock);
+	spin_unlock_irqrestore(&sc->sbm_lock, flags);
 
 	return 0;
 }
@@ -2568,14 +2569,15 @@ static void sbmac_mii_poll(struct net_device *dev)
 static void sbmac_tx_timeout (struct net_device *dev)
 {
 	struct sbmac_softc *sc = netdev_priv(dev);
+	unsigned long flags;
 
-	spin_lock_irq (&sc->sbm_lock);
+	spin_lock_irqsave(&sc->sbm_lock, flags);
 
 
 	dev->trans_start = jiffies;
 	dev->stats.tx_errors++;
 
-	spin_unlock_irq (&sc->sbm_lock);
+	spin_unlock_irqrestore(&sc->sbm_lock, flags);
 
 	printk (KERN_WARNING "%s: Transmit timed out\n",dev->name);
 }
-- 
1.5.5.1

Re: [PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[Jeff Garzik]

On Wed, Sep 17, 2008 at 10:25:37AM +0800, Weiwei Wang wrote:
> Netpoll will call the interrupt handler with interrupts
> disabled when using kgdboe, so spin_lock_irqsave() should
> be used instead of spin_lock_irq() to prevent interrupts
> from being incorrectly enabled.
> 
> Signed-off-by: Weiwei Wang <weiwei.wang@windriver.com>
> ---
>  drivers/net/sb1250-mac.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)

Please send to jeff@garzik.org or jgarzik@pobox.com.

	Jeff

Re: [PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[Ralf Baechle]

On Wed, Sep 17, 2008 at 07:40:51AM -0400, Jeff Garzik wrote:

> On Wed, Sep 17, 2008 at 10:25:37AM +0800, Weiwei Wang wrote:
> > Netpoll will call the interrupt handler with interrupts
> > disabled when using kgdboe, so spin_lock_irqsave() should
> > be used instead of spin_lock_irq() to prevent interrupts
> > from being incorrectly enabled.
> > 
> > Signed-off-by: Weiwei Wang <weiwei.wang@windriver.com>
> > ---
> >  drivers/net/sb1250-mac.c |   12 +++++++-----
> >  1 files changed, 7 insertions(+), 5 deletions(-)
> 
> Please send to jeff@garzik.org or jgarzik@pobox.com.

Jeff - I haven't looked at kgdboe but if he's right half of drivers/net
will need to be fixed ...

  Ralf

Re: [PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[Jeff Garzik]

Ralf Baechle wrote:
> On Wed, Sep 17, 2008 at 07:40:51AM -0400, Jeff Garzik wrote:
> 
>> On Wed, Sep 17, 2008 at 10:25:37AM +0800, Weiwei Wang wrote:
>>> Netpoll will call the interrupt handler with interrupts
>>> disabled when using kgdboe, so spin_lock_irqsave() should
>>> be used instead of spin_lock_irq() to prevent interrupts
>>> from being incorrectly enabled.
>>>
>>> Signed-off-by: Weiwei Wang <weiwei.wang@windriver.com>
>>> ---
>>>  drivers/net/sb1250-mac.c |   12 +++++++-----
>>>  1 files changed, 7 insertions(+), 5 deletions(-)
>> Please send to jeff@garzik.org or jgarzik@pobox.com.
> 
> Jeff - I haven't looked at kgdboe but if he's right half of drivers/net
> will need to be fixed ...

Oh indeed.  I mainly do it on a case-by-case basis where people care.  I 
overall think its a bogus change that deserves pushback, but that 
involves non-networking layers.  In the end, case-by-case application 
seemed to win.

	Jeff

Re: [PATCH] convert sbmac tx to spin_lock_irqsave to prevent early IRQ enable

[Ralf Baechle]

On Thu, Sep 25, 2008 at 03:33:40PM -0400, Jeff Garzik wrote:

>>> On Wed, Sep 17, 2008 at 10:25:37AM +0800, Weiwei Wang wrote:
>>>> Netpoll will call the interrupt handler with interrupts
>>>> disabled when using kgdboe, so spin_lock_irqsave() should
>>>> be used instead of spin_lock_irq() to prevent interrupts
>>>> from being incorrectly enabled.
>>>>
>>>> Signed-off-by: Weiwei Wang <weiwei.wang@windriver.com>
>>>> ---
>>>>  drivers/net/sb1250-mac.c |   12 +++++++-----
>>>>  1 files changed, 7 insertions(+), 5 deletions(-)
>>> Please send to jeff@garzik.org or jgarzik@pobox.com.
>>
>> Jeff - I haven't looked at kgdboe but if he's right half of drivers/net
>> will need to be fixed ...
>
> Oh indeed.  I mainly do it on a case-by-case basis where people care.  I  
> overall think its a bogus change that deserves pushback, but that  
> involves non-networking layers.  In the end, case-by-case application  
> seemed to win.

Turns out kgdboe isn't upstream yet - but netconsole apparently hast the
same issue.

  Ralf