It looks like bands are being disabled in the code for the Marvel Chipset..
What adverse affects are there from having both 2.4 and 5GHz enabled for Marvel Radios? If both bands cannot play next to each other at the same time in one radio, it would still be nice to have the ability for a router with 2 radios running the 5GHz band.
Because the hardware (PHYs, amps, antennas) itself is limited to one band each.
Even if lifting the ban from device tree would (appear) to work, you'd have to deal with low range/ throughput and a significant danger of permanent hardware damage (SWR).
@slh, do the antennas "really" limit the radio to one band each? A laptop WiFi card is capable of 2.4 or 5Ghz communication on-demand.
Where can I find data on the low throughput, and documented SWR caused as a result of failure to cripple a radio?
I understand the enabling both bands on all radios might have an impact on the current LEDE architecture (where are the Band details set, what band should a network use, etc). But this seems like a worthy endeavor.
At the very least users should have the ability to set the Band on their end, instead of having it crammed down their throat.(Use a default which can be overridden by the user) You can see that the hardware vendors are now kicking out "tri-band" devices, and all three radios are identical.
LEDE could have a profound impact by allowing users to set the Band on their devices to meet user needs. An advanced user could set built-in radios to 5Ghz, and add a cheap dongle to support 2.4 (as needed). This would provide the ability to alter bands to meet network needs. Maybe 5Ghz wont work for me, so I need dual band 2.4. Maybe 5GHz is great for me, but I want a radio used just for backhaul.
I'm going to stick with the notion that it has been in the best interest of the router manufacturers to create a myth that a radio is only capable of one band at a time. And that a router can only support one 5Ghz radio at a time. Part of this myth is falling apart when you look at the specs of current vendor "mesh" systems.
LEDE as a framework (netifd and friends) doesn't care, you could have 4 (or more) wlan cards operating in one band, the hardware however does care - and yes, even the antennas matter. These days there are even tri-band devices, which cut the 5 GHz band in half, with one card tuned to the upper frequencies and one to the lower ones - and yes, the hardware doesn't like at all operating in the wrong band (bad range, signal quality, throughout). Just that your notebook is typically designed to cover 2.4- and 5 GHz doesn't mean that all devices need to follow suit - and routers generally don't, be it for saving a few pennies or improving signal quality by tuning for one band each/ only. Neither software nor your beliefs can change the hardware and its physical capabilities and stomping your feet on the ground won't help either.
Narrower band filters are a cheap way to simplify the hardware's HF paths and to improve signal quality with much less efforts required than for wider band widths.