Am 09.05.2025 um 13:59 schrieb Alexander Wilhelm:
Am Fri, May 09, 2025 at 12:54:47PM +0200 schrieb Sebastian Gottschall:
Am 09.05.2025 um 10:43 schrieb Alexander Wilhelm:
Hello devs,
I'd like to understand how TX power setting works on ath11k devices. For example
when I'm using channel 36 for ETSI based regulatory domain, I can set up to 23
dBm. But then I get only 20 dBm as a result. On different channels and/or
regulatory domains I get different reductions. I tried to follow the source
code. As far as I understood is that 'ath11k_mac_txpower_recalc' sets the
correct values and 'ath11k_mac_op_get_txpower' return the different one.
My question is where this reduction offset is encoded. Is it in the module's
firmware or is it part of the boardfile? Thank you in advance.
Best regards
Alexander Wilhelm
the boardfile contains chipset specific calibration data which also defines
the hardware power limits (more specific data also included in the on board
calibration flash of the device or if its a router, in flash memory of the
router itself. in addition it includes a regulatory database which is used
by the firmware for managing the total power. you have also to consider that
the 23dbm are specified without antenna gain.
so if the antenna gain is 3 dbm, you get 20 dbm in total. this antenna gain
may again be specified in the boardfile.
so you will not find your answers in any sourcecode. its all encoded in
binary data.
Sebastian
Alright, thank you Sebastian. Since I'm not using any calibration data on my
router/AP device, all data come from the boardfile. I've also understood that
the power limit reduction is related to antenna gain. I'll ask the radio module
manufacturer to create another boardfile for me that matches the required
antenna gain for my router/AP device.
my answer might be not accurate here. which chipset we are talking about
for ath11k?
Best regards
Alexander Wilhelm
