From ea066d5a91f2610116dcd27054f749e4f07799d8 Mon Sep 17 00:00:00 2001 From: Mohammed Shafi Shajakhan Date: Tue, 23 Nov 2010 20:42:27 +0530 Subject: ath9k: Add support for Adaptive Power Management This feature is to mitigate the problem of certain 3 stream chips that exceed the PCIe power requirements.An EEPROM flag controls which chips have APM enabled which is basically read from miscellaneous configuration element of the EEPROM header. This workaround will reduce power consumption by using 2 Tx chains for Single and Double stream rates (5 GHz only).All self generated frames (regardless of rate) are sent on 2 chains when this feature is enabled(Chip Limitation). Cc: Paul Shaw Signed-off-by: Mohammed Shafi Shajakhan Tested-by: Mohammed Shafi Shajakhan Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/xmit.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'drivers/net/wireless/ath/ath9k/xmit.c') diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index 177a7b1de32..821d3679c6f 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -1506,6 +1506,18 @@ static u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, int pktlen, return duration; } +u8 ath_txchainmask_reduction(struct ath_softc *sc, u8 chainmask, u32 rate) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath9k_channel *curchan = ah->curchan; + if ((sc->sc_flags & SC_OP_ENABLE_APM) && + (curchan->channelFlags & CHANNEL_5GHZ) && + (chainmask == 0x7) && (rate < 0x90)) + return 0x3; + else + return chainmask; +} + static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len) { struct ath_common *common = ath9k_hw_common(sc->sc_ah); @@ -1546,7 +1558,6 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len) rix = rates[i].idx; series[i].Tries = rates[i].count; - series[i].ChSel = common->tx_chainmask; if ((sc->config.ath_aggr_prot && bf_isaggr(bf)) || (rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS)) { @@ -1569,6 +1580,8 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len) if (rates[i].flags & IEEE80211_TX_RC_MCS) { /* MCS rates */ series[i].Rate = rix | 0x80; + series[i].ChSel = ath_txchainmask_reduction(sc, + common->tx_chainmask, series[i].Rate); series[i].PktDuration = ath_pkt_duration(sc, rix, len, is_40, is_sgi, is_sp); if (rix < 8 && (tx_info->flags & IEEE80211_TX_CTL_STBC)) @@ -1576,7 +1589,7 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len) continue; } - /* legcay rates */ + /* legacy rates */ if ((tx_info->band == IEEE80211_BAND_2GHZ) && !(rate->flags & IEEE80211_RATE_ERP_G)) phy = WLAN_RC_PHY_CCK; @@ -1592,6 +1605,12 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len) is_sp = false; } + if (bf->bf_state.bfs_paprd) + series[i].ChSel = common->tx_chainmask; + else + series[i].ChSel = ath_txchainmask_reduction(sc, + common->tx_chainmask, series[i].Rate); + series[i].PktDuration = ath9k_hw_computetxtime(sc->sc_ah, phy, rate->bitrate * 100, len, rix, is_sp); } -- cgit v1.2.3-70-g09d2