Re: [PATCH v2 1/4] mac80211: fix overflow issues in airtime fairness code

[Felix Fietkau <nbd@nbd.name>]

On 11.06.22 22:01, Felix Fietkau wrote:
> The airtime weight calculation overflows with a default weight value of 256
> whenever more than 8ms worth of airtime is reported.
> Bigger weight values impose even smaller limits on maximum airtime values.
> This can mess up airtime based calculations for drivers that don't report
> per-PPDU airtime values, but batch up values instead.
> 
> Fix this by reordering multiplications/shifts and by reducing unnecessary
> intermediate precision (which was lost in a later stage anyway).
> 
> The new shift value limits the maximum weight to 4096, which should be more
> than enough. Any values bigger than that will be rejected
> 
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
Please don't merge this series yet. I'm still investigating reports of 
regressions caused by it.

- Felix