| Message ID | alpine.SOC.1.00.1012100020110.26229@math.ut.ee |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Meelis Roos <mroos@linux.ee> Date: Fri, 10 Dec 2010 01:19:23 +0200 (EET) > In 2.6.37-rc4, hostap_pci init gives a WARNING with backtrace telling > that netif_stop_queue is called before register_netdev. Fix it by moving > this call after register_netdev. Removes the warning and seems to work, > but why is the call to netif_stop_queue needed at all after > register_netdev? > > Signed-off-by: Meelis Roos <mroos@linux.ee> It should simply not touch the queue state at all at this point. Your change would add a race. At the moment the device is registered it can be brought up, and then your code will eroneously modify the queue state. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> > In 2.6.37-rc4, hostap_pci init gives a WARNING with backtrace telling > > that netif_stop_queue is called before register_netdev. Fix it by moving > > this call after register_netdev. Removes the warning and seems to work, > > but why is the call to netif_stop_queue needed at all after > > register_netdev? > > It should simply not touch the queue state at all at this point. > > Your change would add a race. At the moment the device is registered > it can be brought up, and then your code will eroneously modify > the queue state. OK, I can make a simpler patch for that but I would like to understand the original reasons for having netif_stop_queue there. Just a relict or still somehow important? Jouni?
From: Meelis Roos <mroos@linux.ee> Date: Fri, 10 Dec 2010 09:19:51 +0200 (EET) >> > In 2.6.37-rc4, hostap_pci init gives a WARNING with backtrace telling >> > that netif_stop_queue is called before register_netdev. Fix it by moving >> > this call after register_netdev. Removes the warning and seems to work, >> > but why is the call to netif_stop_queue needed at all after >> > register_netdev? >> >> It should simply not touch the queue state at all at this point. >> >> Your change would add a race. At the moment the device is registered >> it can be brought up, and then your code will eroneously modify >> the queue state. > > OK, I can make a simpler patch for that but I would like to understand > the original reasons for having netif_stop_queue there. Just a relict or > still somehow important? I think it was neither. The queue state is "don't care" at this point, and always has been, and a lot of drivers had this unnecessary netif_stop_queue() call there. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c index b7cb165..cc760c5 100644 --- a/drivers/net/wireless/hostap/hostap_hw.c +++ b/drivers/net/wireless/hostap/hostap_hw.c @@ -3253,6 +3253,8 @@ while (0) } printk(KERN_INFO "%s: Registered netdevice %s\n", dev_info, dev->name); + netif_stop_queue(dev); + hostap_init_data(local); return dev; diff --git a/drivers/net/wireless/hostap/hostap_main.c b/drivers/net/wireless/hostap/hostap_main.c index 25a2722..0f1b202 100644 --- a/drivers/net/wireless/hostap/hostap_main.c +++ b/drivers/net/wireless/hostap/hostap_main.c @@ -100,6 +100,7 @@ struct net_device * hostap_add_interface(struct local_info *local, printk(KERN_DEBUG "%s: registered netdevice %s\n", mdev->name, dev->name); + netif_stop_queue(dev); return dev; } @@ -891,7 +892,6 @@ void hostap_setup_dev(struct net_device *dev, local_info_t *local, SET_ETHTOOL_OPS(dev, &prism2_ethtool_ops); - netif_stop_queue(dev); } static int hostap_enable_hostapd(local_info_t *local, int rtnl_locked)
In 2.6.37-rc4, hostap_pci init gives a WARNING with backtrace telling that netif_stop_queue is called before register_netdev. Fix it by moving this call after register_netdev. Removes the warning and seems to work, but why is the call to netif_stop_queue needed at all after register_netdev? Signed-off-by: Meelis Roos <mroos@linux.ee>