ath9k: fix extending the rx timestamp with the hardware TSF
AR5416 and all newer chipsets use a 32 bit rx timestamp, so there
is no need to keep the 15 bit timestamp extending logic around.
This patch removes ath9k_hw_extend_tsf (replaced by a call to
ath9k_hw_gettsf64), and reduces the frequency of TSF reads, which
can improve performance in some cases.
This change also has the side effect of making rx timestamps
more accurate.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 5141cd8..78ef1ae 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -1002,8 +1002,6 @@
struct ieee80211_rx_status *rx_status,
bool *decrypt_error)
{
- struct ath_hw *ah = common->ah;
-
memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
/*
@@ -1018,7 +1016,6 @@
if (ath9k_process_rate(common, hw, rx_stats, rx_status))
return -EINVAL;
- rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
rx_status->band = hw->conf.channel->band;
rx_status->freq = hw->conf.channel->center_freq;
rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
@@ -1100,6 +1097,8 @@
bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
int dma_type;
u8 rx_status_len = ah->caps.rx_status_len;
+ u64 tsf = 0;
+ u32 tsf_lower = 0;
if (edma)
dma_type = DMA_BIDIRECTIONAL;
@@ -1109,6 +1108,9 @@
qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
spin_lock_bh(&sc->rx.rxbuflock);
+ tsf = ath9k_hw_gettsf64(ah);
+ tsf_lower = tsf & 0xffffffff;
+
do {
/* If handling rx interrupt and flush is in progress => exit */
if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
@@ -1141,6 +1143,15 @@
if (flush)
goto requeue;
+ rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
+ if (rs.rs_tstamp > tsf_lower &&
+ unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
+ rxs->mactime -= 0x100000000ULL;
+
+ if (rs.rs_tstamp < tsf_lower &&
+ unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
+ rxs->mactime += 0x100000000ULL;
+
retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
rxs, &decrypt_error);
if (retval)