Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-next

4 files changed, 61 insertions, 52 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/drv.c b/drivers/net/wireless/iwlwifi/pcie/drv.c
index 158669ee4ce5..dc02cb9792af 100644
--- a/drivers/net/wireless/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/iwlwifi/pcie/drv.c
@@ -325,15 +325,15 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	int ret;
 
 	iwl_trans = iwl_trans_pcie_alloc(pdev, ent, cfg);
-	if (iwl_trans == NULL)
-		return -ENOMEM;
+	if (IS_ERR(iwl_trans))
+		return PTR_ERR(iwl_trans);
 
 	pci_set_drvdata(pdev, iwl_trans);
 
 	trans_pcie = IWL_TRANS_GET_PCIE_TRANS(iwl_trans);
 	trans_pcie->drv = iwl_drv_start(iwl_trans, cfg);
 
-	if (IS_ERR_OR_NULL(trans_pcie->drv)) {
+	if (IS_ERR(trans_pcie->drv)) {
 		ret = PTR_ERR(trans_pcie->drv);
 		goto out_free_trans;
 	}
diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c
index 68837d4e9fa0..a4c7aeb786d2 100644
--- a/drivers/net/wireless/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/rx.c
@@ -112,15 +112,16 @@
  */
 static int iwl_rxq_space(const struct iwl_rxq *rxq)
 {
-	int s = rxq->read - rxq->write;
-
-	if (s <= 0)
-		s += RX_QUEUE_SIZE;
-	/* keep some buffer to not confuse full and empty queue */
-	s -= 2;
-	if (s < 0)
-		s = 0;
-	return s;
+	/* Make sure RX_QUEUE_SIZE is a power of 2 */
+	BUILD_BUG_ON(RX_QUEUE_SIZE & (RX_QUEUE_SIZE - 1));
+
+	/*
+	 * There can be up to (RX_QUEUE_SIZE - 1) free slots, to avoid ambiguity
+	 * between empty and completely full queues.
+	 * The following is equivalent to modulo by RX_QUEUE_SIZE and is well
+	 * defined for negative dividends.
+	 */
+	return (rxq->read - rxq->write - 1) & (RX_QUEUE_SIZE - 1);
 }
 
 /*
@@ -1128,6 +1129,7 @@ static irqreturn_t iwl_pcie_isr(int irq, void *data)
 	struct iwl_trans *trans = data;
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	u32 inta, inta_mask;
+	irqreturn_t ret = IRQ_NONE;
 
 	lockdep_assert_held(&trans_pcie->irq_lock);
 
@@ -1176,10 +1178,8 @@ static irqreturn_t iwl_pcie_isr(int irq, void *data)
 	/* the thread will service interrupts and re-enable them */
 	if (likely(inta))
 		return IRQ_WAKE_THREAD;
-	else if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
-		 !trans_pcie->inta)
-		iwl_enable_interrupts(trans);
-	return IRQ_HANDLED;
+
+	ret = IRQ_HANDLED;
 
 none:
 	/* re-enable interrupts here since we don't have anything to service. */
@@ -1188,7 +1188,7 @@ none:
 	    !trans_pcie->inta)
 		iwl_enable_interrupts(trans);
 
-	return IRQ_NONE;
+	return ret;
 }
 
 /* interrupt handler using ict table, with this interrupt driver will
@@ -1207,6 +1207,7 @@ irqreturn_t iwl_pcie_isr_ict(int irq, void *data)
 	u32 val = 0;
 	u32 read;
 	unsigned long flags;
+	irqreturn_t ret = IRQ_NONE;
 
 	if (!trans)
 		return IRQ_NONE;
@@ -1219,7 +1220,7 @@ irqreturn_t iwl_pcie_isr_ict(int irq, void *data)
 	 * use legacy interrupt.
 	 */
 	if (unlikely(!trans_pcie->use_ict)) {
-		irqreturn_t ret = iwl_pcie_isr(irq, data);
+		ret = iwl_pcie_isr(irq, data);
 		spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
 		return ret;
 	}
@@ -1288,17 +1289,9 @@ irqreturn_t iwl_pcie_isr_ict(int irq, void *data)
 	if (likely(inta)) {
 		spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
 		return IRQ_WAKE_THREAD;
-	} else if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
-		 !trans_pcie->inta) {
-		/* Allow interrupt if was disabled by this handler and
-		 * no tasklet was schedules, We should not enable interrupt,
-		 * tasklet will enable it.
-		 */
-		iwl_enable_interrupts(trans);
 	}
 
-	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
-	return IRQ_HANDLED;
+	ret = IRQ_HANDLED;
 
  none:
 	/* re-enable interrupts here since we don't have anything to service.
@@ -1309,5 +1302,5 @@ irqreturn_t iwl_pcie_isr_ict(int irq, void *data)
 		iwl_enable_interrupts(trans);
 
 	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
-	return IRQ_NONE;
+	return ret;
 }
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index e52d1ce1501c..bad95d28d50d 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1386,9 +1386,10 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 
 	trans = kzalloc(sizeof(struct iwl_trans) +
 			sizeof(struct iwl_trans_pcie), GFP_KERNEL);
-
-	if (!trans)
-		return NULL;
+	if (!trans) {
+		err = -ENOMEM;
+		goto out;
+	}
 
 	trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
@@ -1411,10 +1412,9 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 				       PCIE_LINK_STATE_CLKPM);
 	}
 
-	if (pci_enable_device(pdev)) {
-		err = -ENODEV;
+	err = pci_enable_device(pdev);
+	if (err)
 		goto out_no_pci;
-	}
 
 	pci_set_master(pdev);
 
@@ -1483,17 +1483,20 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 				  SLAB_HWCACHE_ALIGN,
 				  NULL);
 
-	if (!trans->dev_cmd_pool)
+	if (!trans->dev_cmd_pool) {
+		err = -ENOMEM;
 		goto out_pci_disable_msi;
+	}
 
 	trans_pcie->inta_mask = CSR_INI_SET_MASK;
 
 	if (iwl_pcie_alloc_ict(trans))
 		goto out_free_cmd_pool;
 
-	if (request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
-				 iwl_pcie_irq_handler,
-				 IRQF_SHARED, DRV_NAME, trans)) {
+	err = request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
+				   iwl_pcie_irq_handler,
+				   IRQF_SHARED, DRV_NAME, trans);
+	if (err) {
 		IWL_ERR(trans, "Error allocating IRQ %d\n", pdev->irq);
 		goto out_free_ict;
 	}
@@ -1512,5 +1515,6 @@ out_pci_disable_device:
 	pci_disable_device(pdev);
 out_no_pci:
 	kfree(trans);
-	return NULL;
+out:
+	return ERR_PTR(err);
 }
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c
index 011167c22da8..f45eb29c2ede 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -65,18 +65,30 @@
  ***************************************************/
 static int iwl_queue_space(const struct iwl_queue *q)
 {
-	int s = q->read_ptr - q->write_ptr;
-
-	if (q->read_ptr > q->write_ptr)
-		s -= q->n_bd;
-
-	if (s <= 0)
-		s += q->n_window;
-	/* keep some reserve to not confuse empty and full situations */
-	s -= 2;
-	if (s < 0)
-		s = 0;
-	return s;
+	unsigned int max;
+	unsigned int used;
+
+	/*
+	 * To avoid ambiguity between empty and completely full queues, there
+	 * should always be less than q->n_bd elements in the queue.
+	 * If q->n_window is smaller than q->n_bd, there is no need to reserve
+	 * any queue entries for this purpose.
+	 */
+	if (q->n_window < q->n_bd)
+		max = q->n_window;
+	else
+		max = q->n_bd - 1;
+
+	/*
+	 * q->n_bd is a power of 2, so the following is equivalent to modulo by
+	 * q->n_bd and is well defined for negative dividends.
+	 */
+	used = (q->write_ptr - q->read_ptr) & (q->n_bd - 1);
+
+	if (WARN_ON(used > max))
+		return 0;
+
+	return max - used;
 }
 
 /*
@@ -826,7 +838,7 @@ static int iwl_pcie_tx_alloc(struct iwl_trans *trans)
 				  sizeof(struct iwl_txq), GFP_KERNEL);
 	if (!trans_pcie->txq) {
 		IWL_ERR(trans, "Not enough memory for txq\n");
-		ret = ENOMEM;
+		ret = -ENOMEM;
 		goto error;
 	}