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authorMichael Buesch <mb@bu3sch.de>2006-10-28 17:52:34 -0500
committerJohn W. Linville <linville@laptop.(none)>2006-10-31 22:15:40 -0500
commit81e171b95d2d06a64465a1e6ab1e2fb864ea2448 (patch)
tree5154832a9d5f54901163f50445324910dcb22d93 /drivers/net/wireless
parent115e222d538e7838bffa0f76409acd9816a0ef32 (diff)
downloadlinux-linaro-android-81e171b95d2d06a64465a1e6ab1e2fb864ea2448.tar.gz
[PATCH] bcm43xx: Fix low-traffic netdev watchdog TX timeouts
This fixes a netdev watchdog timeout problem. The software needs to call netif_tx_disable before running the hardware calibration code. The problem condition 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 <mb@bu3sch.de> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless')
-rw-r--r--drivers/net/wireless/bcm43xx/bcm43xx_main.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_main.c b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
index a94c6d8826f..65edb56107f 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_main.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
@@ -3163,9 +3163,11 @@ static int estimate_periodic_work_badness(unsigned int state)
static void bcm43xx_periodic_work_handler(void *d)
{
struct bcm43xx_private *bcm = d;
+ struct net_device *net_dev = bcm->net_dev;
unsigned long flags;
u32 savedirqs = 0;
int badness;
+ unsigned long orig_trans_start = 0;
mutex_lock(&bcm->mutex);
badness = estimate_periodic_work_badness(bcm->periodic_state);
@@ -3173,7 +3175,18 @@ static void bcm43xx_periodic_work_handler(void *d)
/* Periodic work will take a long time, so we want it to
* be preemtible.
*/
- netif_tx_disable(bcm->net_dev);
+
+ netif_tx_lock_bh(net_dev);
+ /* 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)
+ */
+ orig_trans_start = net_dev->trans_start;
+ net_dev->trans_start = jiffies;
+ netif_stop_queue(net_dev);
+ netif_tx_unlock_bh(net_dev);
+
spin_lock_irqsave(&bcm->irq_lock, flags);
bcm43xx_mac_suspend(bcm);
if (bcm43xx_using_pio(bcm))
@@ -3198,6 +3211,7 @@ static void bcm43xx_periodic_work_handler(void *d)
bcm43xx_pio_thaw_txqueues(bcm);
bcm43xx_mac_enable(bcm);
netif_wake_queue(bcm->net_dev);
+ net_dev->trans_start = orig_trans_start;
}
mmiowb();
spin_unlock_irqrestore(&bcm->irq_lock, flags);