Re: Fwd: [PATCH] bcm43xx: (hopefully) fix watchdog timeouts.
On Wednesday 25 October 2006 02:37, John W. Linville wrote: Michael, It looks like you have a patch that I don't have, one that moves the netif_tx_disable and spin_lock_irqsave outside of the if (badness BADNESS_LIMIT) conditional. Could you pass that one along as well, or correct this patch to match what is in Linus' tree? Well, I'm not sure who moved the tx_disable outside of the conditional. It is not needed. We only need to disable TX on the slowpath (the first branch of the if condition). It does not hurt to disable it always, though. But I will send a new patch against wireless-2.6, which only disables TX for the slowpath and fakes a TX there. But for Greg, the original patch is ok. How was the stable mailing list again? [EMAIL PROTECTED] seems to bounce. -- Greetings Michael. - 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
Re: Fwd: [PATCH] bcm43xx: (hopefully) fix watchdog timeouts.
On Wed, Oct 25, 2006 at 11:38:38AM +0200, Michael Buesch wrote: On Wednesday 25 October 2006 02:37, John W. Linville wrote: Michael, It looks like you have a patch that I don't have, one that moves the netif_tx_disable and spin_lock_irqsave outside of the if (badness BADNESS_LIMIT) conditional. Could you pass that one along as well, or correct this patch to match what is in Linus' tree? Well, I'm not sure who moved the tx_disable outside of the conditional. It is not needed. We only need to disable TX on the slowpath (the first branch of the if condition). It does not hurt to disable it always, though. But I will send a new patch against wireless-2.6, which only disables TX for the slowpath and fakes a TX there. But for Greg, the original patch is ok. How was the stable mailing list again? [EMAIL PROTECTED] seems to bounce. As per the MAINTAINERS file, it is [EMAIL PROTECTED] Please send this there, it will not get lost that way. thanks, greg k-h - 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
Fwd: [PATCH] bcm43xx: (hopefully) fix watchdog timeouts.
This fixes a netdev watchdog timeout problem.
The problem is caused by a needed netif_tx_disable
in the hardware calibration code and can be shown by the
following timegraph.
|---5secs - ~10 jiffies time---|---|OOPS
^ ^
last real TX periodic work stops netif
At OOPS, the following happens:
The watchdog timer triggers, because the timeout of 5secs
is over. The watchdog first checks for stopped TX.
_Usually_ TX is only stopped from the TX handler to indicate
a full TX queue. But this is different. We need to stop TX here,
regardless of the TX queue state. So the watchdog recognizes
the stopped device and assumes it is stopped due to full
TX queues (Which is a _wrong_ assumption in this case). It then
tests how far the last TX has been in the past. If it's more than
5secs (which is the case for low or no traffic), it will fire
a TX timeout.
Signed-off-by: Michael Buesch [EMAIL PROTECTED]
--
John, please apply this bugfix to wireless-2.6.
Greg, as the -stable maintainer, please consider putting this
into 2.6.18.2
Index: linux-2.6.18/drivers/net/wireless/bcm43xx/bcm43xx_main.c
===
--- linux-2.6.18.orig/drivers/net/wireless/bcm43xx/bcm43xx_main.c
2006-10-19 21:30:42.0 +0200
+++ linux-2.6.18/drivers/net/wireless/bcm43xx/bcm43xx_main.c2006-10-19
21:33:28.0 +0200
@@ -3165,7 +3165,15 @@ static void bcm43xx_periodic_work_handle
badness = estimate_periodic_work_badness(bcm-periodic_state);
mutex_lock(bcm-mutex);
+
+ /* We must fake a started transmission here, as we are going to
+* disable TX. If we wouldn't fake a TX, it would be possible to
+* trigger the netdev watchdog, if the last real TX is already
+* some time on the past (slightly less than 5secs)
+*/
+ bcm-net_dev-trans_start = jiffies;
netif_tx_disable(bcm-net_dev);
+
spin_lock_irqsave(bcm-irq_lock, flags);
if (badness BADNESS_LIMIT) {
/* Periodic work will take a long time, so we want it to
--
Greetings Michael.
-
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
Re: Fwd: [PATCH] bcm43xx: (hopefully) fix watchdog timeouts.
Oh, damn crap. Please remove the words fwd and hopefully from the subject. Sorry for the inconvenience. -- Greetings Michael. - 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
Re: Fwd: [PATCH] bcm43xx: (hopefully) fix watchdog timeouts.
Michael,
It looks like you have a patch that I don't have, one that moves the
netif_tx_disable and spin_lock_irqsave outside of the if (badness
BADNESS_LIMIT) conditional.
Could you pass that one along as well, or correct this patch to match
what is in Linus' tree?
Thanks,
John
On Tue, Oct 24, 2006 at 04:31:18PM +0200, Michael Buesch wrote:
This fixes a netdev watchdog timeout problem.
The problem is caused by a needed netif_tx_disable
in the hardware calibration code and can be shown by the
following timegraph.
|---5secs - ~10 jiffies time---|---|OOPS
^ ^
last real TX periodic work stops netif
At OOPS, the following happens:
The watchdog timer triggers, because the timeout of 5secs
is over. The watchdog first checks for stopped TX.
_Usually_ TX is only stopped from the TX handler to indicate
a full TX queue. But this is different. We need to stop TX here,
regardless of the TX queue state. So the watchdog recognizes
the stopped device and assumes it is stopped due to full
TX queues (Which is a _wrong_ assumption in this case). It then
tests how far the last TX has been in the past. If it's more than
5secs (which is the case for low or no traffic), it will fire
a TX timeout.
Signed-off-by: Michael Buesch [EMAIL PROTECTED]
--
John, please apply this bugfix to wireless-2.6.
Greg, as the -stable maintainer, please consider putting this
into 2.6.18.2
Index: linux-2.6.18/drivers/net/wireless/bcm43xx/bcm43xx_main.c
===
--- linux-2.6.18.orig/drivers/net/wireless/bcm43xx/bcm43xx_main.c
2006-10-19 21:30:42.0 +0200
+++ linux-2.6.18/drivers/net/wireless/bcm43xx/bcm43xx_main.c 2006-10-19
21:33:28.0 +0200
@@ -3165,7 +3165,15 @@ static void bcm43xx_periodic_work_handle
badness = estimate_periodic_work_badness(bcm-periodic_state);
mutex_lock(bcm-mutex);
+
+ /* We must fake a started transmission here, as we are going to
+ * disable TX. If we wouldn't fake a TX, it would be possible to
+ * trigger the netdev watchdog, if the last real TX is already
+ * some time on the past (slightly less than 5secs)
+ */
+ bcm-net_dev-trans_start = jiffies;
netif_tx_disable(bcm-net_dev);
+
spin_lock_irqsave(bcm-irq_lock, flags);
if (badness BADNESS_LIMIT) {
/* Periodic work will take a long time, so we want it to
--
Greetings Michael.
-
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
