Wang Chen said the following on 2008-9-6 17:37: >>>> We have some reasons to kill netdev->priv: >>>> 1. netdev->priv is equal to netdev_priv(). >>>> 2. netdev_priv() wraps the calculation of netdev->priv's offset, obviously >>>> netdev_priv() is more flexible than netdev->priv. >>>> But we cann't kill netdev->priv, because so many drivers reference to it >>>> directly. >>>> >>>> OK, becasue Dave S. Miller said, "every direct netdev->priv usage is a bug", >>>> and I want to kill netdev->priv later, I decided to convert all the direct >>>> reference of netdev->priv first. >>>> >>>> Different to readonly reference of netdev->priv, in this driver, netdev->priv >>>> was changed. I use netdev->ml_priv to replace netdev->priv. >>>> >>>> Signed-off-by: Wang Chen <wangchen@xxxxxxxxxxxxxx> >>> Thank you for your patch. However, I do not understand why you didn't >>> simply replace netdev->priv with netdev_priv()? Can you explain? >> Yeah, that would have been my first choice too... >> > > 1. Why I don't use netdev_priv() to replace netdev->priv here? > Because, here >> @@ -2665,7 +2666,7 @@ static struct net_device *init_wifidev(struct airo_info *ai, >> struct net_device *dev = alloc_netdev(0, "wifi%d", wifi_setup); >> if (!dev) >> return NULL; >> - dev->priv = ethdev->priv; >> + dev->ml_priv = ethdev->ml_priv; >> @@ -2766,7 +2767,7 @@ static struct net_device *_init_airo_card( unsigned short irq, int port, >> return NULL; >> } >> >> - ai = dev->priv; >> + ai = dev->ml_priv = netdev_priv(dev); > netdev->priv was changed here, but it shouldn't, the memory was allocated when alloc_netdev and > netdev->priv should always pointed to that memory. > > 2. Why I use netdev->ml_priv here to replace netdev->priv? > In this driver, netdev->priv are shared by multi wifidevs, that means wifidevs need > mid-layer private data, which are all same as their parent netdev. > This usage is same as Dave's commit "syncppp: Fix crashes." > John, do you have any comments about my answer? -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
