2008-09-06 00:52:52

by Christian Lamparter

[permalink] [raw]
Subject: [PATCH 1/3] p54: 32-bit tsf timestamps


tcpdump:
02:15:42.874518 61112184us tsft 48.0 Mb/s 2437 MHz (0x0480) antenna 1 [0x0000000e] CF +QoS Data IV
02:15:42.874557 >>>4356079526us<<< tsft 24.0 Mb/s 2437 MHz (0x0480) antenna 1 [0x0000000e] Acknowledgment
02:15:42.976844 61214513us tsft 1.0 Mb/s 2437 MHz (0x0480) antenna 0 [0x0000000e] Beacon

as one can see on the huge jump, it's very plausible that firmware does not report the
full 64-bit mac time, just the lower 32bit and some kinds of flags...
Therefore if we want a useful timestamp we have to emulate the high bits.

Signed-off-by: Christian Lamparter <[email protected]>
---
John,

these are the last patches with new features for longer time for wireless-next.
---
diff -Nurp a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
--- a/drivers/net/wireless/p54/p54common.c 2008-09-04 11:58:24.000000000 +0200
+++ b/drivers/net/wireless/p54/p54common.c 2008-09-05 21:02:22.000000000 +0200
@@ -426,10 +426,12 @@ EXPORT_SYMBOL_GPL(p54_parse_eeprom);

static int p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb)
{
+ struct p54_common *priv = dev->priv;
struct p54_rx_hdr *hdr = (struct p54_rx_hdr *) skb->data;
struct ieee80211_rx_status rx_status = {0};
u16 freq = le16_to_cpu(hdr->freq);
size_t header_len = sizeof(*hdr);
+ u32 tsf32;

rx_status.signal = hdr->rssi;
/* XX correct? */
@@ -438,7 +440,13 @@ static int p54_rx_data(struct ieee80211_
rx_status.freq = freq;
rx_status.band = IEEE80211_BAND_2GHZ;
rx_status.antenna = hdr->antenna;
- rx_status.mactime = le64_to_cpu(hdr->timestamp);
+
+ tsf32 = le32_to_cpu(hdr->tsf32);
+ if (tsf32 < priv->tsf_low32)
+ priv->tsf_high32++;
+ rx_status.mactime = ((u64)priv->tsf_high32) << 32 | tsf32;
+ priv->tsf_low32 = tsf32;
+
rx_status.flag |= RX_FLAG_TSFT;

if (hdr->magic & cpu_to_le16(0x4000))
@@ -1037,6 +1045,7 @@ static void p54_stop(struct ieee80211_hw
while ((skb = skb_dequeue(&priv->tx_queue)))
kfree_skb(skb);
priv->stop(dev);
+ priv->tsf_high32 = priv->tsf_low32 = 0;
priv->mode = IEEE80211_IF_TYPE_INVALID;
}

diff -Nurp a/drivers/net/wireless/p54/p54common.h b/drivers/net/wireless/p54/p54common.h
--- a/drivers/net/wireless/p54/p54common.h 2008-09-03 21:53:40.000000000 +0200
+++ b/drivers/net/wireless/p54/p54common.h 2008-09-04 14:42:49.000000000 +0200
@@ -185,7 +185,8 @@ struct p54_rx_hdr {
u8 rssi;
u8 quality;
u16 unknown2;
- __le64 timestamp;
+ __le32 tsf32;
+ __le32 unalloc0;
u8 align[0];
} __attribute__ ((packed));

diff -Nurp a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
--- a/drivers/net/wireless/p54/p54.h 2008-09-03 21:41:19.000000000 +0200
+++ b/drivers/net/wireless/p54/p54.h 2008-09-04 14:43:07.000000000 +0200
@@ -87,6 +87,8 @@ struct p54_common {
void *cached_vdcf;
unsigned int fw_var;
unsigned int fw_interface;
+ u32 tsf_low32;
+ u32 tsf_high32;
struct ieee80211_tx_queue_stats tx_stats[8];
void *eeprom;
struct completion eeprom_comp;