On Fri, 2016-11-25 at 11:06 +0100, Arend van Spriel wrote: > > On 11/25/2016 9:25 AM, Johannes Berg wrote: > > Sorry, forgot to reply to this until Luca's email bumped it up... > > > > On Tue, 2016-11-22 at 21:06 +0100, Arend Van Spriel wrote: > > > > > Are we? Currently, the minimum is not checked in nl80211, but that > > > does not say anything about the driver which might validate the > > > interval as well and return an error. > > > > Well, since drivers currently don't return an error (even if they > > ignore the value!) that *does* change the API. > > > > > What made me start looking at this is that in brcmfmac the interval > > > in the request was ignored and a fixed interval was provisioned in > > > the device. I wanted to fix that but was not sure if I needed to > > > check it against our firmware min..max range and what the appropriate > > > error handling should be. If silently changing what user-space is > > > requesting is fine for this, I am happy to make it so. Preferably in > > > nl80211. > > > > I think (agreeing with Luca) bumping it up is fine. > > Fine by me although the "drift over time" reason seems only more reason > to have minimum validation mainly because nowhere is nl80211.h it is > stated that the interval is a "soft" requirement. Now Luca proposes > bumping to minimum should be done in the driver. What is your opinion? > > I will update the kernel doc to clarify what can be expected from the > interval value. Yeah, I was almost sure there was a statement somewhere that the interval is "soft", but there isn't. I was confusing with the match logic, which is clearly documented as not-guaranteed: "...there is no guarantee that the reported BSSs are fully complying with the match sets and userspace needs to be able to ignore them by itself." A clarification in the documentation would be great. -- Luca.
