Under certain conditions, access points with very low signal could be
detected. This signal is too low to estimate a data rate and causes
this L_WARN to fire. Fix this by returning a -ENETUNREACH error code in
case the signal is too low for any of the supported rates.
Similarly to commit
27d302a0 ("band: Add a utility to estimate VHT rx data rate"), this
commit adds an RX data rate estimation utility for HT connections.
This function is meant to supercede a similar function in ie.c. The
current approach results in very optimistic data rate estimates since it
only takes into account the VHT/HT Capabilities IEs. It does not take
into account any local hardware limitations (such as no VHT/HT support),
limited RX MCS sets & number of spatial streams. It also does not take
into account that the AP might not be actually operating on higher
bandwidth channels.
This function is meant to address that by matching peer TX MCS sets with
the local hardware RX MCS set capability. It also takes into account
channel bandwidth capabilities of the local hardware, as well as whether
the AP is actually operating on a wider channel.
Move the band definition out of wiphy.c and into band.[ch]. This is
done to make certain utilities that depend on band information capable
of being tested from unit tests.
The band concept will most likely grow over time. For now, the only
user will be wiphy.c and unit tests, so the structures are kept public.
