d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Enable setting the short-GI bit when TX'ing HT rates but only if the

Browse Source 
hardware supports it.

Since ni->ni_htcap in hostap mode is what the remote end has advertised,
not what has been negotiated/decided, we need to check ourselves what
the current channel width is and what the hardware supports before
enabling short-GI.

It's important that short-GI isn't enabled when it isn't negotiated
and when the hardware doesn't support it (ie, short-gi for 20mhz channels
on any chip < AR9287.)

I've quickly verified this on the AR9285 in 11n mode.
This commit is contained in:
Adrian Chadd 2011-05-30 15:06:57 +00:00
parent 9be25f4a3a
commit 6246be6e58
1 changed files with 14 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/dev/ath/if_ath_tx_ht.c
View File

@ -136,15 +136,23 @@ ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
*/
if (ni->ni_chw == 40)
series[i].RateFlags |= HAL_RATESERIES_2040;
#if 0
/*
* The hardware only supports short-gi in 40mhz mode -
* if later hardware supports it in 20mhz mode, be sure
* to add the relevant check here.
* Set short-GI only if the node has advertised it
* the channel width is suitable, and we support it.
* We don't currently have a "negotiated" set of bits -
* ni_htcap is what the remote end sends, not what this
* node is capable of.
*/
if (ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
if (ni->ni_chw == 40 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
series[i].RateFlags |= HAL_RATESERIES_HALFGI;
if (ni->ni_chw == 20 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
series[i].RateFlags |= HAL_RATESERIES_HALFGI;
#endif
series[i].Rate = rt->info[rix[i]].rateCode;