From 0ec971fdaddfcab72e5104e35774f489991f1f68 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 10 Apr 2017 10:32:58 +0200
Subject: iwlwifi: remove resp_pkt NULL checks

Contrary to what some of the comments say, if rfkill was
asserted the transport will return -ERFKILL instead of
success, if CMD_WANT_SKB was set, so it's not necessary
to check cmd.resp_pkt for being NULL if the return code
was success.

Validate that this is true in iwl_trans_send_cmd().

Most of the other code modifications were done with the
following spatch:
    @@
    struct iwl_host_cmd cmd;
    identifier pkt;
    @@
    <...
    (
    pkt = cmd.resp_pkt;
    ...
    -if (!pkt) { ... }
    |
    pkt = cmd.resp_pkt;
    ...
    -if (WARN_ON(!pkt)) { ... }
    |
    -if (!cmd.resp_pkt) { ... }
    )
    ...>

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c | 5 -----
 1 file changed, 5 deletions(-)

(limited to 'drivers/net/wireless/intel/iwlwifi/mvm/utils.c')

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index 8f4f176e204e..cc5a56818db8 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -168,11 +168,6 @@ int iwl_mvm_send_cmd_status(struct iwl_mvm *mvm, struct iwl_host_cmd *cmd,
 	}
 
 	pkt = cmd->resp_pkt;
-	/* Can happen if RFKILL is asserted */
-	if (!pkt) {
-		ret = 0;
-		goto out_free_resp;
-	}
 
 	resp_len = iwl_rx_packet_payload_len(pkt);
 	if (WARN_ON_ONCE(resp_len != sizeof(*resp))) {
-- 
cgit v1.2.3


From dd32162da4e5b3c9c81adf9a1f6e3a839a35d5f0 Mon Sep 17 00:00:00 2001
From: Liad Kaufman <liad.kaufman@intel.com>
Date: Wed, 5 Apr 2017 16:25:11 +0300
Subject: iwlwifi: mvm: support aggregations on A000 HW

On A000 HW, the SCD rdptr has only 8 bits allocated
for it, thus when checking if a queue is full, or
when checking if the SSN is equal to the TID's
next_reclaimed, A000 HW should trim the SSN.

Fix this by "normalizing" the SSN to wrap around
0xFF when comparing to the next_reclaimed on A000
HW.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c |  2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/ops.c      |  2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/sta.c      | 27 +++++++++++++++++++++--
 drivers/net/wireless/intel/iwlwifi/mvm/sta.h      |  8 ++-----
 drivers/net/wireless/intel/iwlwifi/mvm/tx.c       | 15 ++++++++++---
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c    |  2 +-
 6 files changed, 42 insertions(+), 14 deletions(-)

(limited to 'drivers/net/wireless/intel/iwlwifi/mvm/utils.c')

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 2449be6f95a5..d608ce8305c7 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -2395,7 +2395,7 @@ static void __iwl_mvm_mac_sta_notify(struct ieee80211_hw *hw,
 
 		__set_bit(tid_data->txq_id, &txqs);
 
-		if (iwl_mvm_tid_queued(tid_data) == 0)
+		if (iwl_mvm_tid_queued(mvm, tid_data) == 0)
 			continue;
 
 		__set_bit(tid, &tids);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index 30fc756b5b01..3a8c95162811 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1323,7 +1323,7 @@ static bool iwl_mvm_disallow_offloading(struct iwl_mvm *mvm,
 		 * for offloading in order to prevent reuse of the same
 		 * qos seq counters.
 		 */
-		if (iwl_mvm_tid_queued(tid_data))
+		if (iwl_mvm_tid_queued(mvm, tid_data))
 			continue;
 
 		if (tid_data->state != IWL_AGG_OFF)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 59cd2486a449..0249300c4600 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -2529,6 +2529,7 @@ int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 {
 	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
 	struct iwl_mvm_tid_data *tid_data;
+	u16 normalized_ssn;
 	int txq_id;
 	int ret;
 
@@ -2616,7 +2617,15 @@ int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 			    mvmsta->sta_id, tid, txq_id, tid_data->ssn,
 			    tid_data->next_reclaimed);
 
-	if (tid_data->ssn == tid_data->next_reclaimed) {
+	/*
+	 * In A000 HW, the next_reclaimed index is only 8 bit, so we'll need
+	 * to align the wrap around of ssn so we compare relevant values.
+	 */
+	normalized_ssn = tid_data->ssn;
+	if (mvm->trans->cfg->gen2)
+		normalized_ssn &= 0xff;
+
+	if (normalized_ssn == tid_data->next_reclaimed) {
 		tid_data->state = IWL_AGG_STARTING;
 		ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
 	} else {
@@ -3540,7 +3549,7 @@ void iwl_mvm_sta_modify_sleep_tx_count(struct iwl_mvm *mvm,
 				return;
 			}
 
-			n_queued = iwl_mvm_tid_queued(tid_data);
+			n_queued = iwl_mvm_tid_queued(mvm, tid_data);
 			if (n_queued > remaining) {
 				more_data = true;
 				remaining = 0;
@@ -3722,3 +3731,17 @@ void iwl_mvm_csa_client_absent(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 
 	rcu_read_unlock();
 }
+
+u16 iwl_mvm_tid_queued(struct iwl_mvm *mvm, struct iwl_mvm_tid_data *tid_data)
+{
+	u16 sn = IEEE80211_SEQ_TO_SN(tid_data->seq_number);
+
+	/*
+	 * In A000 HW, the next_reclaimed index is only 8 bit, so we'll need
+	 * to align the wrap around of ssn so we compare relevant values.
+	 */
+	if (mvm->trans->cfg->gen2)
+		sn &= 0xff;
+
+	return ieee80211_sn_sub(sn, tid_data->next_reclaimed);
+}
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.h b/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
index 357ff2bf75c1..05fecbe87da4 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.h
@@ -341,12 +341,6 @@ struct iwl_mvm_tid_data {
 	bool is_tid_active;
 };
 
-static inline u16 iwl_mvm_tid_queued(struct iwl_mvm_tid_data *tid_data)
-{
-	return ieee80211_sn_sub(IEEE80211_SEQ_TO_SN(tid_data->seq_number),
-				tid_data->next_reclaimed);
-}
-
 struct iwl_mvm_key_pn {
 	struct rcu_head rcu_head;
 	struct {
@@ -447,6 +441,8 @@ struct iwl_mvm_sta {
 	u8 avg_energy;
 };
 
+u16 iwl_mvm_tid_queued(struct iwl_mvm *mvm, struct iwl_mvm_tid_data *tid_data);
+
 static inline struct iwl_mvm_sta *
 iwl_mvm_sta_from_mac80211(struct ieee80211_sta *sta)
 {
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index da05801c9ca1..288505114153 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -1129,13 +1129,14 @@ static void iwl_mvm_check_ratid_empty(struct iwl_mvm *mvm,
 	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
 	struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
 	struct ieee80211_vif *vif = mvmsta->vif;
+	u16 normalized_ssn;
 
 	lockdep_assert_held(&mvmsta->lock);
 
 	if ((tid_data->state == IWL_AGG_ON ||
 	     tid_data->state == IWL_EMPTYING_HW_QUEUE_DELBA ||
 	     iwl_mvm_is_dqa_supported(mvm)) &&
-	    iwl_mvm_tid_queued(tid_data) == 0) {
+	    iwl_mvm_tid_queued(mvm, tid_data) == 0) {
 		/*
 		 * Now that this aggregation or DQA queue is empty tell
 		 * mac80211 so it knows we no longer have frames buffered for
@@ -1144,7 +1145,15 @@ static void iwl_mvm_check_ratid_empty(struct iwl_mvm *mvm,
 		ieee80211_sta_set_buffered(sta, tid, false);
 	}
 
-	if (tid_data->ssn != tid_data->next_reclaimed)
+	/*
+	 * In A000 HW, the next_reclaimed index is only 8 bit, so we'll need
+	 * to align the wrap around of ssn so we compare relevant values.
+	 */
+	normalized_ssn = tid_data->ssn;
+	if (mvm->trans->cfg->gen2)
+		normalized_ssn &= 0xff;
+
+	if (normalized_ssn != tid_data->next_reclaimed)
 		return;
 
 	switch (tid_data->state) {
@@ -1488,7 +1497,7 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
 			if (mvmsta->sleep_tx_count) {
 				mvmsta->sleep_tx_count--;
 				if (mvmsta->sleep_tx_count &&
-				    !iwl_mvm_tid_queued(tid_data)) {
+				    !iwl_mvm_tid_queued(mvm, tid_data)) {
 					/*
 					 * The number of frames in the queue
 					 * dropped to 0 even if we sent less
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index cc5a56818db8..dc8104d846f9 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -1181,7 +1181,7 @@ static void iwl_mvm_remove_inactive_tids(struct iwl_mvm *mvm,
 	/* Go over all non-active TIDs, incl. IWL_MAX_TID_COUNT (for mgmt) */
 	for_each_set_bit(tid, &tid_bitmap, IWL_MAX_TID_COUNT + 1) {
 		/* If some TFDs are still queued - don't mark TID as inactive */
-		if (iwl_mvm_tid_queued(&mvmsta->tid_data[tid]))
+		if (iwl_mvm_tid_queued(mvm, &mvmsta->tid_data[tid]))
 			tid_bitmap &= ~BIT(tid);
 	}
 
-- 
cgit v1.2.3


From 6b54ebf73b3e5adc2cab3abc6cb37ca66fa74ae2 Mon Sep 17 00:00:00 2001
From: Luca Coelho <luciano.coelho@intel.com>
Date: Fri, 5 May 2017 16:11:24 +0300
Subject: iwlwifi: mvm: reset the HW before dumping if HW error is detected

If the hardware is stuck, we can't read any of the memory we need to
dump it, so we end up printing only 0xa5a5a5a5, which is useless.

To solve this, poke the hardware by triggering a reset and re-enabling
the clocks if we detect a HW error.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c | 32 ++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'drivers/net/wireless/intel/iwlwifi/mvm/utils.c')

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index dc8104d846f9..e7cc8e05615a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -69,6 +69,7 @@
 #include "iwl-debug.h"
 #include "iwl-io.h"
 #include "iwl-prph.h"
+#include "iwl-csr.h"
 #include "fw-dbg.h"
 #include "mvm.h"
 #include "fw-api-rs.h"
@@ -497,6 +498,7 @@ static void iwl_mvm_dump_lmac_error_log(struct iwl_mvm *mvm, u32 base)
 {
 	struct iwl_trans *trans = mvm->trans;
 	struct iwl_error_event_table table;
+	u32 val;
 
 	if (mvm->cur_ucode == IWL_UCODE_INIT) {
 		if (!base)
@@ -515,6 +517,36 @@ static void iwl_mvm_dump_lmac_error_log(struct iwl_mvm *mvm, u32 base)
 		return;
 	}
 
+	/* check if there is a HW error */
+	val = iwl_trans_read_mem32(trans, base);
+	if (((val & ~0xf) == 0xa5a5a5a0) || ((val & ~0xf) == 0x5a5a5a50)) {
+		int err;
+
+		IWL_ERR(trans, "HW error, resetting before reading\n");
+
+		/* reset the device */
+		iwl_set_bit(trans, CSR_RESET, CSR_RESET_REG_FLAG_SW_RESET);
+		usleep_range(1000, 2000);
+
+		/* set INIT_DONE flag */
+		iwl_set_bit(trans, CSR_GP_CNTRL,
+			    CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
+
+		/* and wait for clock stabilization */
+		if (trans->cfg->device_family == IWL_DEVICE_FAMILY_8000)
+			udelay(2);
+
+		err = iwl_poll_bit(trans, CSR_GP_CNTRL,
+				   CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY,
+				   CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY,
+				   25000);
+		if (err < 0) {
+			IWL_DEBUG_INFO(trans,
+				       "Failed to reset the card for the dump\n");
+			return;
+		}
+	}
+
 	iwl_trans_read_mem_bytes(trans, base, &table, sizeof(table));
 
 	if (ERROR_START_OFFSET <= table.valid * ERROR_ELEM_SIZE) {
-- 
cgit v1.2.3


From 59df97f7223636399f425a5e76586218c48d791e Mon Sep 17 00:00:00 2001
From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Date: Sun, 7 May 2017 13:31:55 +0300
Subject: iwlwifi: mvm: don't mark TIDs that are not idle wrt BA as inactive

A TID may not have traffic but still have a BA agreement
active (or being setup / torn down) since a BA agreement
can be triggered by a debugfs hook.
Just avoid to consider such a TID as inactive to make the
logic safer.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'drivers/net/wireless/intel/iwlwifi/mvm/utils.c')

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index e7cc8e05615a..8ba8b71dd1a4 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -1215,6 +1215,10 @@ static void iwl_mvm_remove_inactive_tids(struct iwl_mvm *mvm,
 		/* If some TFDs are still queued - don't mark TID as inactive */
 		if (iwl_mvm_tid_queued(mvm, &mvmsta->tid_data[tid]))
 			tid_bitmap &= ~BIT(tid);
+
+		/* Don't mark as inactive any TID that has an active BA */
+		if (mvmsta->tid_data[tid].state != IWL_AGG_OFF)
+			tid_bitmap &= ~BIT(tid);
 	}
 
 	/* If all TIDs in the queue are inactive - mark queue as inactive. */
-- 
cgit v1.2.3


From dcfbd67b4b8d5223d5362aac9af267387a32f568 Mon Sep 17 00:00:00 2001
From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Date: Sun, 7 May 2017 15:00:31 +0300
Subject: iwlwifi: add a W/A for a scheduler hardware bug

In case we need to move the scheduler write pointer by
steps of 0x40, 0x80 or 0xc0, the scheduler gets stuck.
This leads to hardware error interrupts with status:
0x5A5A5A5A or alike.

In order to work around this, detect in the transport
layer that we are going to hit this case and tell iwlmvm
to increment the sequence number of the packets. This
allows to keep the requirement that the WiFi sequence
number is in sync with the index in the scheduler Tx queue
and it also allows to avoid the problematic sequence.
This means that from time to time, we will start a queue
from ssn + 1, but that shouldn't be a problem since we
don't switch to new queues for AMPDU now that we have
DQA which allows to keep the same queue while toggling
the AMPDU state.

This bug has been fixed on 9000 devices and up.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/iwl-trans.h     | 13 +++---
 drivers/net/wireless/intel/iwlwifi/mvm/mvm.h       |  2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/sta.c       | 17 ++++++--
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c     | 50 ++++++++++++----------
 drivers/net/wireless/intel/iwlwifi/pcie/internal.h |  2 +-
 drivers/net/wireless/intel/iwlwifi/pcie/tx.c       | 22 +++++++++-
 6 files changed, 72 insertions(+), 34 deletions(-)

(limited to 'drivers/net/wireless/intel/iwlwifi/mvm/utils.c')

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-trans.h b/drivers/net/wireless/intel/iwlwifi/iwl-trans.h
index 2e975c0be045..57db6250a329 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-trans.h
@@ -482,7 +482,9 @@ struct iwl_trans_txq_scd_cfg {
  *	iwl_trans_ac_txq_enable wrapper. fw_alive must have been called before
  *	this one. The op_mode must not configure the HCMD queue. The scheduler
  *	configuration may be %NULL, in which case the hardware will not be
- *	configured. May sleep.
+ *	configured. If true is returned, the operation mode needs to increment
+ *	the sequence number of the packets routed to this queue because of a
+ *	hardware scheduler bug. May sleep.
  * @txq_disable: de-configure a Tx queue to send AMPDUs
  *	Must be atomic
  * @txq_set_shared_mode: change Tx queue shared/unshared marking
@@ -544,7 +546,7 @@ struct iwl_trans_ops {
 	void (*reclaim)(struct iwl_trans *trans, int queue, int ssn,
 			struct sk_buff_head *skbs);
 
-	void (*txq_enable)(struct iwl_trans *trans, int queue, u16 ssn,
+	bool (*txq_enable)(struct iwl_trans *trans, int queue, u16 ssn,
 			   const struct iwl_trans_txq_scd_cfg *cfg,
 			   unsigned int queue_wdg_timeout);
 	void (*txq_disable)(struct iwl_trans *trans, int queue,
@@ -952,7 +954,7 @@ static inline void iwl_trans_txq_disable(struct iwl_trans *trans, int queue,
 	trans->ops->txq_disable(trans, queue, configure_scd);
 }
 
-static inline void
+static inline bool
 iwl_trans_txq_enable_cfg(struct iwl_trans *trans, int queue, u16 ssn,
 			 const struct iwl_trans_txq_scd_cfg *cfg,
 			 unsigned int queue_wdg_timeout)
@@ -961,10 +963,11 @@ iwl_trans_txq_enable_cfg(struct iwl_trans *trans, int queue, u16 ssn,
 
 	if (WARN_ON_ONCE(trans->state != IWL_TRANS_FW_ALIVE)) {
 		IWL_ERR(trans, "%s bad state = %d\n", __func__, trans->state);
-		return;
+		return false;
 	}
 
-	trans->ops->txq_enable(trans, queue, ssn, cfg, queue_wdg_timeout);
+	return trans->ops->txq_enable(trans, queue, ssn,
+				      cfg, queue_wdg_timeout);
 }
 
 static inline void
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index e616472afd45..7171928872de 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1744,7 +1744,7 @@ static inline bool iwl_mvm_vif_low_latency(struct iwl_mvm_vif *mvmvif)
 }
 
 /* hw scheduler queue config */
-void iwl_mvm_enable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
+bool iwl_mvm_enable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
 			u16 ssn, const struct iwl_trans_txq_scd_cfg *cfg,
 			unsigned int wdg_timeout);
 int iwl_mvm_tvqm_enable_txq(struct iwl_mvm *mvm, int mac80211_queue,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 0249300c4600..aa41ee8ed916 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -758,7 +758,7 @@ static int iwl_mvm_sta_alloc_queue(struct iwl_mvm *mvm,
 	bool using_inactive_queue = false, same_sta = false;
 	unsigned long disable_agg_tids = 0;
 	enum iwl_mvm_agg_state queue_state;
-	bool shared_queue = false;
+	bool shared_queue = false, inc_ssn;
 	int ssn;
 	unsigned long tfd_queue_mask;
 	int ret;
@@ -885,8 +885,12 @@ static int iwl_mvm_sta_alloc_queue(struct iwl_mvm *mvm,
 	}
 
 	ssn = IEEE80211_SEQ_TO_SN(le16_to_cpu(hdr->seq_ctrl));
-	iwl_mvm_enable_txq(mvm, queue, mac_queue, ssn, &cfg,
-			   wdg_timeout);
+	inc_ssn = iwl_mvm_enable_txq(mvm, queue, mac_queue,
+				     ssn, &cfg, wdg_timeout);
+	if (inc_ssn) {
+		ssn = (ssn + 1) & IEEE80211_SCTL_SEQ;
+		le16_add_cpu(&hdr->seq_ctrl, 0x10);
+	}
 
 	/*
 	 * Mark queue as shared in transport if shared
@@ -898,6 +902,13 @@ static int iwl_mvm_sta_alloc_queue(struct iwl_mvm *mvm,
 		iwl_trans_txq_set_shared_mode(mvm->trans, queue, true);
 
 	spin_lock_bh(&mvmsta->lock);
+	/*
+	 * This looks racy, but it is not. We have only one packet for
+	 * this ra/tid in our Tx path since we stop the Qdisc when we
+	 * need to allocate a new TFD queue.
+	 */
+	if (inc_ssn)
+		mvmsta->tid_data[tid].seq_number += 0x10;
 	mvmsta->tid_data[tid].txq_id = queue;
 	mvmsta->tid_data[tid].is_tid_active = true;
 	mvmsta->tfd_queue_msk |= BIT(queue);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index 8ba8b71dd1a4..0093e78dd571 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -757,35 +757,39 @@ int iwl_mvm_tvqm_enable_txq(struct iwl_mvm *mvm, int mac80211_queue,
 	return queue;
 }
 
-void iwl_mvm_enable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
+bool iwl_mvm_enable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
 			u16 ssn, const struct iwl_trans_txq_scd_cfg *cfg,
 			unsigned int wdg_timeout)
 {
+	struct iwl_scd_txq_cfg_cmd cmd = {
+		.scd_queue = queue,
+		.action = SCD_CFG_ENABLE_QUEUE,
+		.window = cfg->frame_limit,
+		.sta_id = cfg->sta_id,
+		.ssn = cpu_to_le16(ssn),
+		.tx_fifo = cfg->fifo,
+		.aggregate = cfg->aggregate,
+		.tid = cfg->tid,
+	};
+	bool inc_ssn;
+
 	if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
-		return;
+		return false;
 
 	/* Send the enabling command if we need to */
-	if (iwl_mvm_update_txq_mapping(mvm, queue, mac80211_queue,
-				       cfg->sta_id, cfg->tid)) {
-		struct iwl_scd_txq_cfg_cmd cmd = {
-			.scd_queue = queue,
-			.action = SCD_CFG_ENABLE_QUEUE,
-			.window = cfg->frame_limit,
-			.sta_id = cfg->sta_id,
-			.ssn = cpu_to_le16(ssn),
-			.tx_fifo = cfg->fifo,
-			.aggregate = cfg->aggregate,
-			.tid = cfg->tid,
-		};
-
-		iwl_trans_txq_enable_cfg(mvm->trans, queue, ssn, NULL,
-					 wdg_timeout);
-		WARN(iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, 0,
-					  sizeof(struct iwl_scd_txq_cfg_cmd),
-					  &cmd),
-		     "Failed to configure queue %d on FIFO %d\n", queue,
-		     cfg->fifo);
-	}
+	if (!iwl_mvm_update_txq_mapping(mvm, queue, mac80211_queue,
+					cfg->sta_id, cfg->tid))
+		return false;
+
+	inc_ssn = iwl_trans_txq_enable_cfg(mvm->trans, queue, ssn,
+					   NULL, wdg_timeout);
+	if (inc_ssn)
+		le16_add_cpu(&cmd.ssn, 1);
+
+	WARN(iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, 0, sizeof(cmd), &cmd),
+	     "Failed to configure queue %d on FIFO %d\n", queue, cfg->fifo);
+
+	return inc_ssn;
 }
 
 int iwl_mvm_disable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
index 644c0e583f32..4295b8409720 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -516,7 +516,7 @@ int iwl_pcie_gen2_tx_init(struct iwl_trans *trans);
 void iwl_pcie_tx_start(struct iwl_trans *trans, u32 scd_base_addr);
 int iwl_pcie_tx_stop(struct iwl_trans *trans);
 void iwl_pcie_tx_free(struct iwl_trans *trans);
-void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int queue, u16 ssn,
+bool iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int queue, u16 ssn,
 			       const struct iwl_trans_txq_scd_cfg *cfg,
 			       unsigned int wdg_timeout);
 void iwl_trans_pcie_txq_disable(struct iwl_trans *trans, int queue,
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
index 6b19ccc0ae41..9087b1fccaee 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -1277,13 +1277,14 @@ static int iwl_pcie_txq_set_ratid_map(struct iwl_trans *trans, u16 ra_tid,
  * combined with Traffic ID (QOS priority), in format used by Tx Scheduler */
 #define BUILD_RAxTID(sta_id, tid)	(((sta_id) << 4) + (tid))
 
-void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
+bool iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 			       const struct iwl_trans_txq_scd_cfg *cfg,
 			       unsigned int wdg_timeout)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct iwl_txq *txq = trans_pcie->txq[txq_id];
 	int fifo = -1;
+	bool scd_bug = false;
 
 	if (test_and_set_bit(txq_id, trans_pcie->queue_used))
 		WARN_ONCE(1, "queue %d already used - expect issues", txq_id);
@@ -1324,6 +1325,23 @@ void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 
 			ssn = txq->read_ptr;
 		}
+	} else {
+		/*
+		 * If we need to move the SCD write pointer by steps of
+		 * 0x40, 0x80 or 0xc0, it gets stuck. Avoids this and let
+		 * the op_mode know by returning true later.
+		 * Do this only in case cfg is NULL since this trick can
+		 * be done only if we have DQA enabled which is true for mvm
+		 * only. And mvm never sets a cfg pointer.
+		 * This is really ugly, but this is the easiest way out for
+		 * this sad hardware issue.
+		 * This bug has been fixed on devices 9000 and up.
+		 */
+		scd_bug = !trans->cfg->mq_rx_supported &&
+			!((ssn - txq->write_ptr) & 0x3f) &&
+			(ssn != txq->write_ptr);
+		if (scd_bug)
+			ssn++;
 	}
 
 	/* Place first TFD at index corresponding to start sequence number.
@@ -1367,6 +1385,8 @@ void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 				    "Activate queue %d WrPtr: %d\n",
 				    txq_id, ssn & 0xff);
 	}
+
+	return scd_bug;
 }
 
 void iwl_trans_pcie_txq_set_shared_mode(struct iwl_trans *trans, u32 txq_id,
-- 
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