[PATCH] chelsio: add MSI support

Using MSI can avoid sharing IRQ and associated overhead.
Tested on PCI-X.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/chelsio/common.h b/drivers/net/chelsio/common.h
index 55f1eaa..b265941 100644 (file)
--- a/drivers/net/chelsio/common.h
+++ b/drivers/net/chelsio/common.h
@@ -228,6 +228,7 @@ struct adapter_params {
        unsigned short chip_revision;
        unsigned char  chip_version;
        unsigned char  is_asic;
+       unsigned char  has_msi;
 };
 
 struct link_config {

diff --git a/drivers/net/chelsio/cxgb2.c b/drivers/net/chelsio/cxgb2.c
index 571aa06..0ca5b07 100644 (file)
--- a/drivers/net/chelsio/cxgb2.c
+++ b/drivers/net/chelsio/cxgb2.c
@@ -107,6 +107,10 @@ static int t1powersave = 1;        /* HW default is powersave mode. */
 module_param(t1powersave, int, 0);
 MODULE_PARM_DESC(t1powersave, "Enable/Disable T1 powersaving mode");
 
+static int disable_msi = 0;
+module_param(disable_msi, int, 0);
+MODULE_PARM_DESC(disable_msi, "Disable Message Signaled Interrupt (MSI)");
+
 static const char pci_speed[][4] = {
        "33", "66", "100", "133"
 };
@@ -215,11 +219,19 @@ static int cxgb_up(struct adapter *adapter)
        }
 
        t1_interrupts_clear(adapter);
-       if ((err = request_irq(adapter->pdev->irq,
-                              t1_select_intr_handler(adapter), IRQF_SHARED,
-                              adapter->name, adapter))) {
+
+       adapter->params.has_msi = !disable_msi && pci_enable_msi(adapter->pdev) == 0;
+       err = request_irq(adapter->pdev->irq,
+                         t1_select_intr_handler(adapter),
+                         adapter->params.has_msi ? 0 : IRQF_SHARED,
+                         adapter->name, adapter);
+       if (err) {
+               if (adapter->params.has_msi)
+                       pci_disable_msi(adapter->pdev);
+
                goto out_err;
        }
+
        t1_sge_start(adapter->sge);
        t1_interrupts_enable(adapter);
  out_err:
@@ -234,6 +246,8 @@ static void cxgb_down(struct adapter *adapter)
        t1_sge_stop(adapter->sge);
        t1_interrupts_disable(adapter);
        free_irq(adapter->pdev->irq, adapter);
+       if (adapter->params.has_msi)
+               pci_disable_msi(adapter->pdev);
 }
 
 static int cxgb_open(struct net_device *dev)