netxen: fix legacy interrupts

Fix legacy interrupt mode for NX3031 chips, read pci interrupt state
in hardware to guard against spurious interrupt.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

2 files changed, 34 insertions, 17 deletions

diff --git a/drivers/net/netxen/netxen_nic_hdr.h b/drivers/net/netxen/netxen_nic_hdr.h
index ccf6d70064bc..e8e8d73f6ed7 100644
--- a/drivers/net/netxen/netxen_nic_hdr.h
+++ b/drivers/net/netxen/netxen_nic_hdr.h
@@ -843,9 +843,11 @@ enum {
 
 #define PCIE_SETUP_FUNCTION     (0x12040)
 #define PCIE_SETUP_FUNCTION2    (0x12048)
+#define PCIE_MISCCFG_RC         (0x1206c)
 #define PCIE_TGT_SPLIT_CHICKEN  (0x12080)
 #define PCIE_CHICKEN3           (0x120c8)
 
+#define ISR_INT_STATE_REG       (NETXEN_PCIX_PS_REG(PCIE_MISCCFG_RC))
 #define PCIE_MAX_MASTER_SPLIT   (0x14048)
 
 #define NETXEN_PORT_MODE_NONE           0
@@ -861,6 +863,7 @@ enum {
 #define NETXEN_CAM_RAM_DMA_WATCHDOG_CTRL                (0x14)
 
 #define ISR_MSI_INT_TRIGGER(FUNC) (NETXEN_PCIX_PS_REG(PCIX_MSI_F(FUNC)))
+#define ISR_LEGACY_INT_TRIGGERED(VAL)   (((VAL) & 0x300) == 0x200)
 
 /*
  * PCI Interrupt Vector Values.
diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 153b391917e4..320d010678cd 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -166,7 +166,8 @@ static void netxen_nic_disable_int(struct netxen_adapter *adapter)
         if (!NETXEN_IS_MSI_FAMILY(adapter)) {
                 do {
                         adapter->pci_write_immediate(adapter,
-                                        ISR_INT_TARGET_STATUS, 0xffffffff);
+                                        adapter->legacy_intr.tgt_status_reg,
+                                        0xffffffff);
                         mask = adapter->pci_read_immediate(adapter,
                                         ISR_INT_VECTOR);
                         if (!(mask & 0x80))
@@ -175,7 +176,7 @@ static void netxen_nic_disable_int(struct netxen_adapter *adapter)
                 } while (--retries);
 
                 if (!retries) {
-                        printk(KERN_NOTICE "%s: Failed to disable interrupt completely\n",
+                        printk(KERN_NOTICE "%s: Failed to disable interrupt\n",
                                         netxen_nic_driver_name);
                 }
         } else {
@@ -190,8 +191,6 @@ static void netxen_nic_enable_int(struct netxen_adapter *adapter)
 {
         u32 mask;
 
-        DPRINTK(1, INFO, "Entered ISR Enable \n");
-
         if (adapter->intr_scheme != -1 &&
                 adapter->intr_scheme != INTR_SCHEME_PERPORT) {
                 switch (adapter->ahw.board_type) {
@@ -213,16 +212,13 @@ static void netxen_nic_enable_int(struct netxen_adapter *adapter)
 
         if (!NETXEN_IS_MSI_FAMILY(adapter)) {
                 mask = 0xbff;
-                if (adapter->intr_scheme != -1 &&
-                        adapter->intr_scheme != INTR_SCHEME_PERPORT) {
+                if (adapter->intr_scheme == INTR_SCHEME_PERPORT)
+                        adapter->pci_write_immediate(adapter,
+                                adapter->legacy_intr.tgt_mask_reg, mask);
+                else
                         adapter->pci_write_normalize(adapter,
                                         CRB_INT_VECTOR, 0);
-                }
-                adapter->pci_write_immediate(adapter,
-                                ISR_INT_TARGET_MASK, mask);
         }
-
-        DPRINTK(1, INFO, "Done with enable Int\n");
 }
 
 static int nx_set_dma_mask(struct netxen_adapter *adapter, uint8_t revision_id)
@@ -1538,15 +1534,33 @@ static irqreturn_t netxen_intr(int irq, void *data)
         struct netxen_adapter *adapter = data;
         u32 our_int = 0;
 
-        our_int = adapter->pci_read_normalize(adapter, CRB_INT_VECTOR);
-        /* not our interrupt */
-        if ((our_int & (0x80 << adapter->portnum)) == 0)
+        u32 status = 0;
+
+        status = adapter->pci_read_immediate(adapter, ISR_INT_VECTOR);
+
+        if (!(status & adapter->legacy_intr.int_vec_bit))
                 return IRQ_NONE;
 
-        if (adapter->intr_scheme == INTR_SCHEME_PERPORT) {
-                /* claim interrupt */
-                adapter->pci_write_normalize(adapter, CRB_INT_VECTOR,
+        if (adapter->ahw.revision_id >= NX_P3_B1) {
+                /* check interrupt state machine, to be sure */
+                status = adapter->pci_read_immediate(adapter,
+                                ISR_INT_STATE_REG);
+                if (!ISR_LEGACY_INT_TRIGGERED(status))
+                        return IRQ_NONE;
+
+        } else if (NX_IS_REVISION_P2(adapter->ahw.revision_id)) {
+
+                our_int = adapter->pci_read_normalize(adapter, CRB_INT_VECTOR);
+                /* not our interrupt */
+                if ((our_int & (0x80 << adapter->portnum)) == 0)
+                        return IRQ_NONE;
+
+                if (adapter->intr_scheme == INTR_SCHEME_PERPORT) {
+                        /* claim interrupt */
+                        adapter->pci_write_normalize(adapter,
+                                CRB_INT_VECTOR,
                                 our_int & ~((u32)(0x80 << adapter->portnum)));
+                }
         }
 
         netxen_handle_int(adapter);