alx: refactor msi enablement and disablement

Introduce a new flag field for the advanced interrupt capatibilities and add
new functions to enable and disable msi interrupts. These functions will be
extended later to cover msi-x interrupts.

We enable msi interrupts earlier in alx_init_intr because with msi-x and multi
queue support the number of queues must be set before we allocate resources for
the rx and tx paths.

Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 26 insertions, 9 deletions

diff --git a/drivers/net/ethernet/atheros/alx/alx.h b/drivers/net/ethernet/atheros/alx/alx.h
index 8fc93c5f6abc..16ca3f4fa2cc 100644
--- a/drivers/net/ethernet/atheros/alx/alx.h
+++ b/drivers/net/ethernet/atheros/alx/alx.h
@@ -76,6 +76,9 @@ enum alx_device_quirks {
         ALX_DEV_QUIRK_MSI_INTX_DISABLE_BUG = BIT(0),
 };
 
+#define ALX_FLAG_USING_MSIX     BIT(0)
+#define ALX_FLAG_USING_MSI      BIT(1)
+
 struct alx_priv {
         struct net_device *dev;
 
@@ -105,7 +108,7 @@ struct alx_priv {
 
         u16 msg_enable;
 
-        bool msi;
+        int flags;
 
         /* protects hw.stats */
         spinlock_t stats_lock;
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index d29a4f3102d6..6dc1539205eb 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -620,6 +620,22 @@ static void alx_config_vector_mapping(struct alx_priv *alx)
         alx_write_mem32(hw, ALX_MSI_ID_MAP, 0);
 }
 
+static void alx_init_intr(struct alx_priv *alx, bool msix)
+{
+        if (!(alx->flags & ALX_FLAG_USING_MSIX)) {
+                if (!pci_enable_msi(alx->hw.pdev))
+                        alx->flags |= ALX_FLAG_USING_MSI;
+        }
+}
+
+static void alx_disable_advanced_intr(struct alx_priv *alx)
+{
+        if (alx->flags & ALX_FLAG_USING_MSI) {
+                pci_disable_msi(alx->hw.pdev);
+                alx->flags &= ~ALX_FLAG_USING_MSI;
+        }
+}
+
 static void alx_irq_enable(struct alx_priv *alx)
 {
         struct alx_hw *hw = &alx->hw;
@@ -650,9 +666,7 @@ static int alx_request_irq(struct alx_priv *alx)
 
         msi_ctrl = (hw->imt >> 1) << ALX_MSI_RETRANS_TM_SHIFT;
 
-        if (!pci_enable_msi(alx->hw.pdev)) {
-                alx->msi = true;
-
+        if (alx->flags & ALX_FLAG_USING_MSI) {
                 alx_write_mem32(hw, ALX_MSI_RETRANS_TIMER,
                                 msi_ctrl | ALX_MSI_MASK_SEL_LINE);
                 err = request_irq(pdev->irq, alx_intr_msi, 0,
@@ -660,6 +674,7 @@ static int alx_request_irq(struct alx_priv *alx)
                 if (!err)
                         goto out;
                 /* fall back to legacy interrupt */
+                alx->flags &= ~ALX_FLAG_USING_MSI;
                 pci_disable_msi(alx->hw.pdev);
         }
 
@@ -678,10 +693,7 @@ static void alx_free_irq(struct alx_priv *alx)
 
         free_irq(pdev->irq, alx);
 
-        if (alx->msi) {
-                pci_disable_msi(alx->hw.pdev);
-                alx->msi = false;
-        }
+        alx_disable_advanced_intr(alx);
 }
 
 static int alx_identify_hw(struct alx_priv *alx)
@@ -847,6 +859,8 @@ static int __alx_open(struct alx_priv *alx, bool resume)
 {
         int err;
 
+        alx_init_intr(alx, false);
+
         if (!resume)
                 netif_carrier_off(alx->dev);
 
@@ -1236,7 +1250,7 @@ static void alx_poll_controller(struct net_device *netdev)
 {
         struct alx_priv *alx = netdev_priv(netdev);
 
-        if (alx->msi)
+        if (alx->flags & ALX_FLAG_USING_MSI)
                 alx_intr_msi(0, alx);
         else
                 alx_intr_legacy(0, alx);