On Wed, Jan 10, 2007 at 06:12:29PM +0100, Thibaut VARENE wrote:
> On 1/9/07, Thibaut VARENE <[EMAIL PROTECTED]> wrote:
> >On 1/9/07, Dale Farnsworth <[EMAIL PROTECTED]> wrote:
> >>
> >> Thank you Thibaut. Please try the following patch:
> >>
> >> From: Dale Farnsworth <[EMAIL PROTECTED]>
> >>
> >> Reserve one unused descriptor in the TX ring
> >> to facilitate testing for when the ring is full.
> >
> >Dale,
> >
> >tried it and unfortunately:
>
> Also, I don't know if you read that bit, but everytime I reboot the
> box immediately after a crash, the NIC gets a bogus (always the same
> it seems) MAC address, and I have to reboot one more time to get back
> to the "normal" MAC address.
>
> Dunno if that hints anything though.
There is something in the code about MAC writing and saving
some config during initialization, so probably it's possible
if reinitialization was broken.
I tried to look more into the code and here are my (maybe
wrong) conclusions:
- It looks like something could be broken during tx descs
freeing or eth_tx_timeout_task. I compared the timeout code
with e100 and tg3 and have a feeling mv643xx_eth is doing
less but I'm not able to estimate the importance of this.
- Such errors, IMHO, could be possible with races and not
enough locking, and btw. I think suspected function isn't
properly locked: mp->tx_desc_count in while condition isn't
protected at all. Below I attach a patch proposal but I'm
not sure some irq off or spin_lock isn't also needed
elswere. If it's only locking it would be suitable to do
the test with a kernel compiled without PREEMPT and SMP,
but if irqs nothing should change...
Regards,
Jarek P.
PS: alas I didn't even check compiling - I had no time to
find all compile dependencies of this driver
---
Signed-off-by: Jarek Poplawski <[EMAIL PROTECTED]>
---
diff -Nurp linux-2.6.20-rc4-/drivers/net/mv643xx_eth.c
linux-2.6.20-rc4/drivers/net/mv643xx_eth.c
--- linux-2.6.20-rc4-/drivers/net/mv643xx_eth.c 2006-12-18 08:57:52.000000000
+0100
+++ linux-2.6.20-rc4/drivers/net/mv643xx_eth.c 2007-01-11 08:55:34.000000000
+0100
@@ -312,8 +312,8 @@ int mv643xx_eth_free_tx_descs(struct net
int count;
int released = 0;
+ spin_lock_irqsave(&mp->lock, flags);
while (mp->tx_desc_count > 0) {
- spin_lock_irqsave(&mp->lock, flags);
tx_index = mp->tx_used_desc_q;
desc = &mp->p_tx_desc_area[tx_index];
cmd_sts = desc->cmd_sts;
@@ -348,8 +348,10 @@ int mv643xx_eth_free_tx_descs(struct net
dev_kfree_skb_irq(skb);
released = 1;
+ spin_lock_irqsave(&mp->lock, flags);
}
+ spin_unlock_irqrestore(&mp->lock, flags);
return released;
}
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
