diff options
author | Benjamin Li <benl@squareup.com> | 2021-10-27 10:03:04 -0700 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2021-11-01 16:18:37 +0200 |
commit | f02e1cc2a84693a649d94a7584291d88f31fd5fa (patch) | |
tree | eec8ea6c6237d2477237aff7c3d4a3542f6ff8d3 | |
parent | df008741dd62bd3bc8733fe568415fb01b3e65c5 (diff) |
wcn36xx: implement flush op to speed up connected scan
Without ieee80211_ops->flush implemented to empty HW queues, mac80211 will
do a 100ms dead wait after stopping SW queues, before leaving the operating
channel to resume a software connected scan[1].
(see ieee80211_scan_state_resume)
This wait is correctly included in the calculation for whether or not
we've exceeded max off-channel time, as it occurs after sending the null
frame with PS bit set. Thus, with 125 ms max off-channel time we only
have 25 ms of scan time, which technically isn't even enough to scan one
channel (although mac80211 always scans at least one channel per off-
channel window).
Moreover, for passive probes we end up spending at least 100 ms + 111 ms
(IEEE80211_PASSIVE_CHANNEL_TIME) "off-channel"[2], which exceeds the listen
interval of 200 ms that we provide in our association request frame. That's
technically out-of-spec.
[1]: Until recently, wcn36xx performed software (rather than FW-offloaded)
scanning when 5GHz channels are requested. This apparent limitation is now
resolved -- see commit 1395f8a6a4d5 ("wcn36xx: Enable hardware scan offload
for 5Ghz band").
[2]: in quotes because about 100 ms of it is still on-channel but with PS
set
Signed-off-by: Benjamin Li <benl@squareup.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211027170306.555535-3-benl@squareup.com
-rw-r--r-- | drivers/net/wireless/ath/wcn36xx/dxe.c | 47 | ||||
-rw-r--r-- | drivers/net/wireless/ath/wcn36xx/dxe.h | 1 | ||||
-rw-r--r-- | drivers/net/wireless/ath/wcn36xx/main.c | 11 |
3 files changed, 59 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/ath/wcn36xx/dxe.c index aff04ef66266..fd627c9f3d40 100644 --- a/drivers/net/wireless/ath/wcn36xx/dxe.c +++ b/drivers/net/wireless/ath/wcn36xx/dxe.c @@ -834,6 +834,53 @@ unlock: return ret; } +static bool _wcn36xx_dxe_tx_channel_is_empty(struct wcn36xx_dxe_ch *ch) +{ + unsigned long flags; + struct wcn36xx_dxe_ctl *ctl_bd_start, *ctl_skb_start; + struct wcn36xx_dxe_ctl *ctl_bd, *ctl_skb; + bool ret = true; + + spin_lock_irqsave(&ch->lock, flags); + + /* Loop through ring buffer looking for nonempty entries. */ + ctl_bd_start = ch->head_blk_ctl; + ctl_bd = ctl_bd_start; + ctl_skb_start = ctl_bd_start->next; + ctl_skb = ctl_skb_start; + do { + if (ctl_skb->skb) { + ret = false; + goto unlock; + } + ctl_bd = ctl_skb->next; + ctl_skb = ctl_bd->next; + } while (ctl_skb != ctl_skb_start); + +unlock: + spin_unlock_irqrestore(&ch->lock, flags); + return ret; +} + +int wcn36xx_dxe_tx_flush(struct wcn36xx *wcn) +{ + int i = 0; + + /* Called with mac80211 queues stopped. Wait for empty HW queues. */ + do { + if (_wcn36xx_dxe_tx_channel_is_empty(&wcn->dxe_tx_l_ch) && + _wcn36xx_dxe_tx_channel_is_empty(&wcn->dxe_tx_h_ch)) { + return 0; + } + /* This ieee80211_ops callback is specifically allowed to + * sleep. + */ + usleep_range(1000, 1100); + } while (++i < 100); + + return -EBUSY; +} + int wcn36xx_dxe_init(struct wcn36xx *wcn) { int reg_data = 0, ret; diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.h b/drivers/net/wireless/ath/wcn36xx/dxe.h index 31b81b7547a3..26a31edf52e9 100644 --- a/drivers/net/wireless/ath/wcn36xx/dxe.h +++ b/drivers/net/wireless/ath/wcn36xx/dxe.h @@ -466,5 +466,6 @@ int wcn36xx_dxe_tx_frame(struct wcn36xx *wcn, struct wcn36xx_tx_bd *bd, struct sk_buff *skb, bool is_low); +int wcn36xx_dxe_tx_flush(struct wcn36xx *wcn); void wcn36xx_dxe_tx_ack_ind(struct wcn36xx *wcn, u32 status); #endif /* _DXE_H_ */ diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c index 06558f5cdeb9..a8b841511484 100644 --- a/drivers/net/wireless/ath/wcn36xx/main.c +++ b/drivers/net/wireless/ath/wcn36xx/main.c @@ -1281,6 +1281,16 @@ static void wcn36xx_ipv6_addr_change(struct ieee80211_hw *hw, } #endif +static void wcn36xx_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif, + u32 queues, bool drop) +{ + struct wcn36xx *wcn = hw->priv; + + if (wcn36xx_dxe_tx_flush(wcn)) { + wcn36xx_err("Failed to flush hardware tx queues\n"); + } +} + static const struct ieee80211_ops wcn36xx_ops = { .start = wcn36xx_start, .stop = wcn36xx_stop, @@ -1308,6 +1318,7 @@ static const struct ieee80211_ops wcn36xx_ops = { #if IS_ENABLED(CONFIG_IPV6) .ipv6_addr_change = wcn36xx_ipv6_addr_change, #endif + .flush = wcn36xx_flush, CFG80211_TESTMODE_CMD(wcn36xx_tm_cmd) }; |