On Mon, 6 Apr 2020 at 18:17, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Mon, 2020-04-06 at 15:44 +0300, Kalle Valo wrote: > > > > > user-space ieee80211_register_hw() RX IRQ > > > +++++++++++++++++++++++++++++++++++++++++++++ > > > | | | > > > |<---wlan0---wiphy_register() | > > > |----start wlan0---->| | > > > | |<---IRQ---(RX packet) > > > | Kernel crash | > > > | due to unallocated | > > > | workqueue. | > > [snip] > > > I have understood that no frames should be received until mac80211 calls > > struct ieee80211_ops::start: > > > > * @start: Called before the first netdevice attached to the hardware > > * is enabled. This should turn on the hardware and must turn on > > * frame reception (for possibly enabled monitor interfaces.) > > True, but I think he's saying that you can actually add and configure an > interface as soon as the wiphy is registered? Indeed, it's a call to "struct ieee80211_ops::start" just after wiphy is registered that causes the frame to be received leading to RX IRQ. > > The "wlan0" is kinda wrong there, should be "phy0" I guess, and then > interface added from iw? Okay, will update the sequence diagram. -Sumit > > johannes >
