Re: [PATCH] ath5k: switch to rate table based lookup

Jonas Jelonek [off-list ref] wrote:

Switching from legacy usage of ieee80211_get_tx_rates() lookup to direct
rate table lookup in struct ieee80211_sta->rates.

The current rate control API allows drivers to directly get rates from
ieee80211_sta->rates. ath5k is currently one of the legacy drivers that
perform translation/merge with the internal rate table via
ieee80211_get_tx_rates provided by rate control API.
For our upcoming changes to rate control API and the implementation of
transmit power control, this patch changes the behaviour. The call to
ieee80211_get_tx_rates and subsequent calls are also avoided. ath5k now
directly reads rates from sta->rates into its internal rate table. Cause
ath5k does not rely on the rate array in SKB->CB, this is not considered
anymore except for the first entry (used for probing).

Tested this on a PCEngines ALIX with CMP9-GP miniPCI wifi card (Atheros
AR5213A). Generated traffic between AP and multiple STAs before and
after applying the patch and simultaneously measured throughput and
captured rc_stats. Comparison resulted in same rate selection and no
performance loss between both runs.

Co-developed-by: Thomas Huehn <redacted>
Signed-off-by: Thomas Huehn <redacted>
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
Signed-off-by: Kalle Valo <redacted>

Patch applied to ath-next branch of ath.git, thanks.

a5d862da9105 ath5k: switch to rate table based lookup

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20211215215042.637-1-jelonek.jonas@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches