2009-07-07 17:08:12

by Christian Lamparter

[permalink] [raw]
Subject: [RESEND][PATCH] p54: re-enable power save feature

This patch re-enables p54's power save features and adds a workaround
which temporarily alters the device's power state in order to allow
ps-polls to be sent and buffered data to be retrieved during psm.

Signed-off-by: Christian Lamparter <[email protected]>
---
diff --git a/drivers/net/wireless/p54/fwio.c b/drivers/net/wireless/p54/fwio.c
index 178efbc..9bff43d 100644
--- a/drivers/net/wireless/p54/fwio.c
+++ b/drivers/net/wireless/p54/fwio.c
@@ -584,7 +584,8 @@ int p54_set_ps(struct p54_common *priv)
unsigned int i;
u16 mode;

- if (priv->hw->conf.flags & IEEE80211_CONF_PS)
+ if (priv->hw->conf.flags & IEEE80211_CONF_PS &&
+ !priv->powersave_override)
mode = P54_PSM | P54_PSM_BEACON_TIMEOUT | P54_PSM_DTIM |
P54_PSM_CHECKSUM | P54_PSM_MCBC;
else
@@ -606,8 +607,8 @@ int p54_set_ps(struct p54_common *priv)

psm->beacon_rssi_skip_max = 200;
psm->rssi_delta_threshold = 0;
- psm->nr = 10;
- psm->exclude[0] = 0;
+ psm->nr = 1;
+ psm->exclude[0] = WLAN_EID_TIM;

p54_tx(priv, skb);
return 0;
diff --git a/drivers/net/wireless/p54/lmac.h b/drivers/net/wireless/p54/lmac.h
index 0496cff..af35cfc 100644
--- a/drivers/net/wireless/p54/lmac.h
+++ b/drivers/net/wireless/p54/lmac.h
@@ -548,4 +548,7 @@ int p54_upload_key(struct p54_common *priv, u8 algo, int slot,
int p54_download_eeprom(struct p54_common *priv, void *buf,
u16 offset, u16 len);

+/* utility */
+u8 *p54_find_ie(struct sk_buff *skb, u8 ie);
+
#endif /* LMAC_H */
diff --git a/drivers/net/wireless/p54/main.c b/drivers/net/wireless/p54/main.c
index f9b4f6a..42abf34 100644
--- a/drivers/net/wireless/p54/main.c
+++ b/drivers/net/wireless/p54/main.c
@@ -65,51 +65,64 @@ static int p54_set_tim(struct ieee80211_hw *dev, struct ieee80211_sta *sta,
return p54_update_beacon_tim(priv, sta->aid, set);
}

-static int p54_beacon_format_ie_tim(struct sk_buff *skb)
+u8 *p54_find_ie(struct sk_buff *skb, u8 ie)
{
- /*
- * the good excuse for this mess is ... the firmware.
- * The dummy TIM MUST be at the end of the beacon frame,
- * because it'll be overwritten!
- */
-
struct ieee80211_mgmt *mgmt = (void *)skb->data;
u8 *pos, *end;

if (skb->len <= sizeof(mgmt))
- return -EINVAL;
+ return NULL;

pos = (u8 *)mgmt->u.beacon.variable;
end = skb->data + skb->len;
while (pos < end) {
if (pos + 2 + pos[1] > end)
- return -EINVAL;
+ return NULL;

- if (pos[0] == WLAN_EID_TIM) {
- u8 dtim_len = pos[1];
- u8 dtim_period = pos[3];
- u8 *next = pos + 2 + dtim_len;
+ if (pos[0] == ie)
+ return pos;

- if (dtim_len < 3)
- return -EINVAL;
+ pos += 2 + pos[1];
+ }
+ return NULL;
+}

- memmove(pos, next, end - next);
+static int p54_beacon_format_ie_tim(struct sk_buff *skb)
+{
+ /*
+ * the good excuse for this mess is ... the firmware.
+ * The dummy TIM MUST be at the end of the beacon frame,
+ * because it'll be overwritten!
+ */
+ u8 *tim;
+ u8 dtim_len;
+ u8 dtim_period;
+ u8 *next;

- if (dtim_len > 3)
- skb_trim(skb, skb->len - (dtim_len - 3));
+ tim = p54_find_ie(skb, WLAN_EID_TIM);
+ if (!tim)
+ return 0;

- pos = end - (dtim_len + 2);
+ dtim_len = tim[1];
+ dtim_period = tim[3];
+ next = tim + 2 + dtim_len;

- /* add the dummy at the end */
- pos[0] = WLAN_EID_TIM;
- pos[1] = 3;
- pos[2] = 0;
- pos[3] = dtim_period;
- pos[4] = 0;
- return 0;
- }
- pos += 2 + pos[1];
- }
+ if (dtim_len < 3)
+ return -EINVAL;
+
+ memmove(tim, next, skb_tail_pointer(skb) - next);
+
+ if (dtim_len > 3)
+ skb_trim(skb, skb->len - (dtim_len - 3));
+
+ tim = skb_tail_pointer(skb) - (dtim_len + 2);
+
+ /* add the dummy at the end */
+ tim[0] = WLAN_EID_TIM;
+ tim[1] = 3;
+ tim[2] = 0;
+ tim[3] = dtim_period;
+ tim[4] = 0;
return 0;
}

@@ -384,6 +397,9 @@ static void p54_bss_info_changed(struct ieee80211_hw *dev,
priv->wakeup_timer = info->beacon_int *
info->dtim_period * 5;
p54_setup_mac(priv);
+ } else {
+ priv->wakeup_timer = 500;
+ priv->aid = 0;
}
}

@@ -517,6 +533,9 @@ struct ieee80211_hw *p54_init_common(size_t priv_data_len)
skb_queue_head_init(&priv->tx_pending);
dev->flags = IEEE80211_HW_RX_INCLUDES_FCS |
IEEE80211_HW_SIGNAL_DBM |
+ IEEE80211_HW_SUPPORTS_PS |
+ IEEE80211_HW_PS_NULLFUNC_STACK |
+ IEEE80211_HW_BEACON_FILTER |
IEEE80211_HW_NOISE_DBM;

dev->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
diff --git a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
index 19d085c..6772ed5 100644
--- a/drivers/net/wireless/p54/p54.h
+++ b/drivers/net/wireless/p54/p54.h
@@ -208,6 +208,7 @@ struct p54_common {
u32 tsf_low32, tsf_high32;
u32 basic_rate_mask;
u16 aid;
+ bool powersave_override;
__le32 beacon_req_id;

/* cryptographic engine information */
diff --git a/drivers/net/wireless/p54/txrx.c b/drivers/net/wireless/p54/txrx.c
index 31fda17..ea074a6 100644
--- a/drivers/net/wireless/p54/txrx.c
+++ b/drivers/net/wireless/p54/txrx.c
@@ -285,6 +285,45 @@ static int p54_rssi_to_dbm(struct p54_common *priv, int rssi)
priv->rssical_db[band].add) / 4;
}

+/*
+ * Even if the firmware is capable of dealing with incoming traffic,
+ * while dozing, we have to prepared in case mac80211 uses PS-POLL
+ * to retrieve outstanding frames from our AP.
+ * (see comment in net/mac80211/mlme.c @ line 1993)
+ */
+static void p54_pspoll_workaround(struct p54_common *priv, struct sk_buff *skb)
+{
+ struct ieee80211_hdr *hdr = (void *) skb->data;
+ struct ieee80211_tim_ie *tim_ie;
+ u8 *tim;
+ u8 tim_len;
+ bool new_psm;
+
+ /* only beacons have a TIM IE */
+ if (!ieee80211_is_beacon(hdr->frame_control))
+ return;
+
+ if (!priv->aid)
+ return;
+
+ /* only consider beacons from the associated BSSID */
+ if (compare_ether_addr(hdr->addr3, priv->bssid))
+ return;
+
+ tim = p54_find_ie(skb, WLAN_EID_TIM);
+ if (!tim)
+ return;
+
+ tim_len = tim[1];
+ tim_ie = (struct ieee80211_tim_ie *) &tim[2];
+
+ new_psm = ieee80211_check_tim(tim_ie, tim_len, priv->aid);
+ if (new_psm != priv->powersave_override) {
+ priv->powersave_override = new_psm;
+ p54_set_ps(priv);
+ }
+}
+
static int p54_rx_data(struct p54_common *priv, struct sk_buff *skb)
{
struct p54_rx_data *hdr = (struct p54_rx_data *) skb->data;
@@ -337,6 +376,9 @@ static int p54_rx_data(struct p54_common *priv, struct sk_buff *skb)

skb_pull(skb, header_len);
skb_trim(skb, le16_to_cpu(hdr->len));
+ if (unlikely(priv->hw->conf.flags & IEEE80211_CONF_PS))
+ p54_pspoll_workaround(priv, skb);
+
ieee80211_rx_irqsafe(priv->hw, skb);

queue_delayed_work(priv->hw->workqueue, &priv->work,