CVSROOT: /cvs
Module name: src
Changes by: s...@cvs.openbsd.org 2019/12/18 02:52:15
Modified files:
sys/dev/pci : if_iwm.c if_iwmvar.h
sys/net80211 : ieee80211_mira.c ieee80211_mira.h
Log message:
Re-enable firmware-based Tx retries at lower rates for iwm(4).
Firmware-based Tx retries were disabled when it was found that MiRA
makes better choices while probing with a constant Tx retry rate.
Before that change, high Tx rates looked better than they actually
were. The change resulted in less retries and thus higher throughput
because a lower, but actually working, initial Tx rate eventually
became the preferred choice.
However, disallowing retries at lower rates also resulted in increased
amounts of observable packet loss, especially while the connection to
the AP was still fresh and bad Tx rates had not been discovered yet.
To get the best of both worlds, use a constant Tx rate for retries while
MiRA is probing and otherwise allow firmware fallback to lower rates.
tested by Tracey Emery, pamela, jasper, and myself, on 7265/8265/9260
