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.

(Incorporates patch originally posted as "p54: fix beacon template dtim
IE corruption". -- JWL)

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/p54/fwio.c b/drivers/net/wireless/p54/fwio.c
index dc4f3f5..349375f 100644 (file)
--- a/drivers/net/wireless/p54/fwio.c
+++ b/drivers/net/wireless/p54/fwio.c
@@ -585,7 +585,8 @@ 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
@@ -607,8 +608,8 @@ 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 (file)
--- 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..c9a0545 100644 (file)
--- 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;
+
+       if (dtim_len < 3)
+               return -EINVAL;
+
+       memmove(tim, next, skb_tail_pointer(skb) - next);
+       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;
+
+       if (dtim_len > 3)
+               skb_trim(skb, skb->len - (dtim_len - 3));
 
-                       /* 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];
-       }
        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 (file)
--- 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 6426d2c..01eadb1 100644 (file)
--- a/drivers/net/wireless/p54/txrx.c
+++ b/drivers/net/wireless/p54/txrx.c
@@ -288,6 +288,45 @@ 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;
@@ -340,6 +379,9 @@ 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,