[PATCH 1/4] iwlegacy: small refactoring of il_{stop,wake}_queue

[PATCH 1/4] iwlegacy: small refactoring of il_{stop,wake}_queue

[Stanislaw Gruszka]

Tested-by: Jake Edge <jake@lwn.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/common.h | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/iwlegacy/common.h b/drivers/net/wireless/iwlegacy/common.h
index 4caaf52..67da89b 100644
--- a/drivers/net/wireless/iwlegacy/common.h
+++ b/drivers/net/wireless/iwlegacy/common.h
@@ -2257,6 +2257,19 @@ il_set_swq_id(struct il_tx_queue *txq, u8 ac, u8 hwq)
 }
 
 static inline void
+_il_wake_queue(struct il_priv *il, u8 ac)
+{
+	if (atomic_dec_return(&il->queue_stop_count[ac]) <= 0)
+		ieee80211_wake_queue(il->hw, ac);
+}
+
+static inline void
+_il_stop_queue(struct il_priv *il, u8 ac)
+{
+	if (atomic_inc_return(&il->queue_stop_count[ac]) > 0)
+		ieee80211_stop_queue(il->hw, ac);
+}
+static inline void
 il_wake_queue(struct il_priv *il, struct il_tx_queue *txq)
 {
 	u8 queue = txq->swq_id;
@@ -2264,8 +2277,7 @@ il_wake_queue(struct il_priv *il, struct il_tx_queue *txq)
 	u8 hwq = (queue >> 2) & 0x1f;
 
 	if (test_and_clear_bit(hwq, il->queue_stopped))
-		if (atomic_dec_return(&il->queue_stop_count[ac]) <= 0)
-			ieee80211_wake_queue(il->hw, ac);
+		_il_wake_queue(il, ac);
 }
 
 static inline void
@@ -2276,8 +2288,7 @@ il_stop_queue(struct il_priv *il, struct il_tx_queue *txq)
 	u8 hwq = (queue >> 2) & 0x1f;
 
 	if (!test_and_set_bit(hwq, il->queue_stopped))
-		if (atomic_inc_return(&il->queue_stop_count[ac]) > 0)
-			ieee80211_stop_queue(il->hw, ac);
+		_il_stop_queue(il, ac);
 }
 
 #ifdef ieee80211_stop_queue
-- 
1.7.11.7

[PATCH 2/4] iwlegacy: add il_{stop,wake}_queues_by_reason functions

[Stanislaw Gruszka]

Add functions that will stop/wake all queues. Make them safe
regarding multiple calls and when some ac are stopped/woke
independently.

Tested-by: Jake Edge <jake@lwn.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/common.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/wireless/iwlegacy/common.h b/drivers/net/wireless/iwlegacy/common.h
index 67da89b..83f8ed8 100644
--- a/drivers/net/wireless/iwlegacy/common.h
+++ b/drivers/net/wireless/iwlegacy/common.h
@@ -1299,6 +1299,8 @@ struct il_priv {
 	/* queue refcounts */
 #define IL_MAX_HW_QUEUES	32
 	unsigned long queue_stopped[BITS_TO_LONGS(IL_MAX_HW_QUEUES)];
+#define IL_STOP_REASON_PASSIVE	0
+	unsigned long stop_reason;
 	/* for each AC */
 	atomic_t queue_stop_count[4];
 
@@ -2291,6 +2293,26 @@ il_stop_queue(struct il_priv *il, struct il_tx_queue *txq)
 		_il_stop_queue(il, ac);
 }
 
+static inline void
+il_wake_queues_by_reason(struct il_priv *il, int reason)
+{
+	u8 ac;
+
+	if (test_and_clear_bit(reason, &il->stop_reason))
+		for (ac = 0; ac < 4; ac++)
+			_il_wake_queue(il, ac);
+}
+
+static inline void
+il_stop_queues_by_reason(struct il_priv *il, int reason)
+{
+	u8 ac;
+
+	if (!test_and_set_bit(reason, &il->stop_reason))
+		for (ac = 0; ac < 4; ac++)
+			_il_stop_queue(il, ac);
+}
+
 #ifdef ieee80211_stop_queue
 #undef ieee80211_stop_queue
 #endif
-- 
1.7.11.7

[PATCH 3/4] iwl4965: workaround for firmware frame tx rejection

[Stanislaw Gruszka]

Firmware can reject to transmit frame on passive channel, when it
did not yet received any frame with valid CRC on that channel.
Workaround this problem in the driver.

Tested-by: Jake Edge <jake@lwn.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/4965-mac.c | 18 ++++++++++++++++++
 drivers/net/wireless/iwlegacy/common.c   | 11 +++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
index 9a95045..1c44bb5 100644
--- a/drivers/net/wireless/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -588,6 +588,11 @@ il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
 		return;
 	}
 
+	if (unlikely(test_bit(IL_STOP_REASON_PASSIVE, &il->stop_reason))) {
+		il_wake_queues_by_reason(il, IL_STOP_REASON_PASSIVE);
+		D_INFO("Woke queues - frame received on passive channel\n");
+	}
+
 	/* In case of HW accelerated crypto and bad decryption, drop */
 	if (!il->cfg->mod_params->sw_crypto &&
 	    il_set_decrypted_flag(il, hdr, ampdu_status, stats))
@@ -2806,6 +2811,19 @@ il4965_hdl_tx(struct il_priv *il, struct il_rx_buf *rxb)
 		return;
 	}
 
+	/*
+	 * Firmware will not transmit frame on passive channel, if it not yet
+	 * received some valid frame on that channel. When this error happen
+	 * we have to wait until firmware will unblock itself i.e. when we
+	 * note received beacon or other frame. We unblock queues in
+	 * il4965_pass_packet_to_mac80211 or in il_mac_bss_info_changed.
+	 */
+	if (unlikely((status & TX_STATUS_MSK) == TX_STATUS_FAIL_PASSIVE_NO_RX) &&
+	    il->iw_mode == NL80211_IFTYPE_STATION) {
+		il_stop_queues_by_reason(il, IL_STOP_REASON_PASSIVE);
+		D_INFO("Stopped queues - RX waiting on passive channel\n");
+	}
+
 	spin_lock_irqsave(&il->sta_lock, flags);
 	if (txq->sched_retry) {
 		const u32 scd_ssn = il4965_get_scd_ssn(tx_resp);
diff --git a/drivers/net/wireless/iwlegacy/common.c b/drivers/net/wireless/iwlegacy/common.c
index e9a3cbc..3195aad 100644
--- a/drivers/net/wireless/iwlegacy/common.c
+++ b/drivers/net/wireless/iwlegacy/common.c
@@ -5307,6 +5307,17 @@ il_mac_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		D_MAC80211("BSSID %pM\n", bss_conf->bssid);
 
 		/*
+		 * On passive channel we wait with blocked queues to see if
+		 * there is traffic on that channel. If no frame will be
+		 * received (what is very unlikely since scan detects AP on
+		 * that channel, but theoretically possible), mac80211 associate
+		 * procedure will time out and mac80211 will call us with NULL
+		 * bssid. We have to unblock queues on such condition.
+		 */
+		if (is_zero_ether_addr(bss_conf->bssid))
+			il_wake_queues_by_reason(il, IL_STOP_REASON_PASSIVE);
+
+		/*
 		 * If there is currently a HW scan going on in the background,
 		 * then we need to cancel it, otherwise sometimes we are not
 		 * able to authenticate (FIXME: why ?)
-- 
1.7.11.7

[PATCH 4/4] iwl3945: workaround for firmware frame tx rejection

[Stanislaw Gruszka]

Firmware can reject to transmit frame on passive channel, when it
did not yet received any frame with valid CRC on that channel.
Workaround this problem in the driver.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/3945.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/wireless/iwlegacy/3945.c b/drivers/net/wireless/iwlegacy/3945.c
index dc1e6da..c092033 100644
--- a/drivers/net/wireless/iwlegacy/3945.c
+++ b/drivers/net/wireless/iwlegacy/3945.c
@@ -331,6 +331,19 @@ il3945_hdl_tx(struct il_priv *il, struct il_rx_buf *rxb)
 		return;
 	}
 
+	/*
+	 * Firmware will not transmit frame on passive channel, if it not yet
+	 * received some valid frame on that channel. When this error happen
+	 * we have to wait until firmware will unblock itself i.e. when we
+	 * note received beacon or other frame. We unblock queues in
+	 * il3945_pass_packet_to_mac80211 or in il_mac_bss_info_changed.
+	 */
+	if (unlikely((status & TX_STATUS_MSK) == TX_STATUS_FAIL_PASSIVE_NO_RX) &&
+	    il->iw_mode == NL80211_IFTYPE_STATION) {
+		il_stop_queues_by_reason(il, IL_STOP_REASON_PASSIVE);
+		D_INFO("Stopped queues - RX waiting on passive channel\n");
+	}
+
 	txq->time_stamp = jiffies;
 	info = IEEE80211_SKB_CB(txq->skbs[txq->q.read_ptr]);
 	ieee80211_tx_info_clear_status(info);
@@ -488,6 +501,11 @@ il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb,
 		return;
 	}
 
+	if (unlikely(test_bit(IL_STOP_REASON_PASSIVE, &il->stop_reason))) {
+		il_wake_queues_by_reason(il, IL_STOP_REASON_PASSIVE);
+		D_INFO("Woke queues - frame received on passive channel\n");
+	}
+
 	skb = dev_alloc_skb(128);
 	if (!skb) {
 		IL_ERR("dev_alloc_skb failed\n");
-- 
1.7.11.7

[PATCH 5/4] Revert "iwl4965: workaround connection regression on passive channel"

[Stanislaw Gruszka]

This reverts commit dd9c46408fdc07098333655ff27edf8cac8d9fcf.

With "iwl{4965,3495): workaround for firmware frame tx rejection"
patches we can enable IEEE80211_HW_REPORTS_TX_ACK_STATUS again.

Tested-by: Jake Edge <jake@lwn.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/4965-mac.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
index 1c44bb5..d287fd2 100644
--- a/drivers/net/wireless/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -5759,7 +5759,8 @@ il4965_mac_setup_register(struct il_priv *il, u32 max_probe_length)
 	hw->flags =
 	    IEEE80211_HW_SIGNAL_DBM | IEEE80211_HW_AMPDU_AGGREGATION |
 	    IEEE80211_HW_NEED_DTIM_BEFORE_ASSOC | IEEE80211_HW_SPECTRUM_MGMT |
-	    IEEE80211_HW_SUPPORTS_PS | IEEE80211_HW_SUPPORTS_DYNAMIC_PS;
+	    IEEE80211_HW_REPORTS_TX_ACK_STATUS | IEEE80211_HW_SUPPORTS_PS |
+	    IEEE80211_HW_SUPPORTS_DYNAMIC_PS;
 	if (il->cfg->sku & IL_SKU_N)
 		hw->flags |=
 		    IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS |
-- 
1.7.11.7