Messages in this thread | | | Subject | Re: [PATCH RFC] cfg80211: add new command for reporting wiphy crashes | From | Johannes Berg <> | Date | Thu, 26 Sep 2019 13:55:04 +0200 |
| |
On Thu, 2019-09-26 at 13:52 +0200, Rafał Miłecki wrote: > > Indeed my main concert is AP mode. I'm afraid that cfg80211 doesn't > cache all settings, consider e.g. nl80211_start_ap(). It builds > struct cfg80211_ap_settings using info from nl80211 message and > passes it to the driver (rdev_start_ap()). Once it's done it > caches only a small subset of all setup data. > > In other words driver doesn't have enough info to recover interfaces > setup.
So the driver can cache it, just like mac80211.
You can't seriously be suggesting that the driver doesn't *have* enough information - everything passed through it :)
> I meant that hardware has been recovered & is operational again (driver > can talk to it). I expected user space to reconfigure all interfaces > using the same settings that were used on previous run. > > If driver were able to recover interfaces setup on its own (with a help > of cfg80211) then user space wouldn't need to be involved.
The driver can do it, mac80211 does. It's just a matter of what the driver will do or not.
> First of all I was wondering how to handle interfaces creation. After a > firmware crash we have: > 1) Interfaces created in Linux > 2) No corresponsing interfaces in firmware
> Syncing that (re-creating in-firmware firmwares) may be a bit tricky > depending on a driver and hardware.
We do that in mac80211, it works fine. Why would it be tricky?
If something fails, I think we force that interface to go down.
> For some cases it could be easier to > delete all interfaces and ask user space to setup wiphy (create required > interfaces) again. I'm not sure if that's acceptable though? > > If we agree interfaces should stay and driver simply should configure > firmware properly, then we need all data as explained earlier. struct > cfg80211_ap_settings is not available during runtime. How should we > handle that problem?
You can cache it in the driver in whatever format makes sense.
> I was aiming for a brutal force solution: just make user space > interfaces need a full setup just at they were just created.
You can still do that btw, just unregister and re-register the wiphy.
johannes
| |