Hi Arend, On Tue, 2016-11-22 at 13:31 +0000, Arend van Spriel wrote: > The interval for scheduled scan may have a minimum value for > the device. Allow drivers to specify a minimum value in the > struct wiphy so user-space interval values can be validated > against it. > > Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> > --- I'm not sure this is necessary, because the interval is a "soft" requirement, there being no guarantee on the accuracy of the intervals. The minimum interval a firmware can support is probably variable, depending on how long time it takes for a scan to complete. Let's say it takes 1 second to scan a certain amount of channels. In this case, the minimum interval is probably 1 second (i.e. you can start a new scan immediately after the first one completed). Now, if you're scanning more channels and it takes, say, 4 seconds to complete, the minimum interval would be 4 seconds. The iwlwifi firmware treats the interval as the amount of time to wait *after* one scan cycle completes before starting the cycle. Since sched scan is mostly used while the system is suspended, the interval can be quite large and the accuracy really doesn't matter. The absoulte time when the scan cycles occur will drift over time, but does it matter? So, for firmwares that really need to get a minimum value, I think bumping up to the minimum allowed if the provided value is too low, should be done in the driver. -- Cheers, Luca.
