CVSROOT: /cvs
Module name: src
Changes by: s...@cvs.openbsd.org 2021/10/11 03:03:22
Modified files:
sys/dev/pci : if_iwm.c if_iwmreg.h if_iwmvar.h
Log message:
Add support for 802.11n 40MHz channels to the iwm(4) driver.
According to 11n MCS index tables our maximum data rate is now
300 Mbit/s at MCS 15, excluding protocol overhead. I have measured
up to 200Mbit/s of effective throughput on clean 5GHz channels.
The driver enables use of 40MHz channels automatically as long as the
access point announces support for such channels in its beacons.
In case 40MHz transmissions fail we ask firmware to retry with a
20MHz transmission.
There is no integration with ifconfig yet, so use of 40MHz is not yet
displayed there. In the meantime, tcpdump(8) can be used to check if
the current access point supports 40MHz:
tcpdump -n -i iwm0 -v -y IEEE802_11_RADIO -s 4096 type mgt and subtype beacon
Channel width is displayed in the HT operation information element, where
a 40MHz channels looks like this: htop=<40MHz chan X:Y ...>
Tested:
7260: florian, bcallah
7265: landry
8260: bket
8265: stsp, abieber, Matthias Schmidt, Josh Rickmar, empee on mastodon
9560: stsp
