[SCSI] stex: add MSI support

This adds the MSI support (default 0=off)

Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index de6c30e..c4eb5c1 100644 (file)
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -292,11 +292,15 @@ struct st_hba {
        struct st_ccb *wait_ccb;
 
        unsigned int mu_status;
-       int out_req_cnt;
-
        unsigned int cardtype;
+       int msi_enabled;
+       int out_req_cnt;
 };
 
+static int msi;
+module_param(msi, int, 0);
+MODULE_PARM_DESC(msi, "Enable Message Signaled Interrupts(0=off, 1=on)");
+
 static const char console_inq_page[] =
 {
        0x03,0x00,0x03,0x03,0xFA,0x00,0x00,0x30,
@@ -1041,6 +1045,40 @@ static int stex_set_dma_mask(struct pci_dev * pdev)
        return ret;
 }
 
+static int stex_request_irq(struct st_hba *hba)
+{
+       struct pci_dev *pdev = hba->pdev;
+       int status;
+
+       if (msi) {
+               status = pci_enable_msi(pdev);
+               if (status != 0)
+                       printk(KERN_ERR DRV_NAME
+                               "(%s): error %d setting up MSI\n",
+                               pci_name(pdev), status);
+               else
+                       hba->msi_enabled = 1;
+       } else
+               hba->msi_enabled = 0;
+
+       status = request_irq(pdev->irq, stex_intr, IRQF_SHARED, DRV_NAME, hba);
+
+       if (status != 0) {
+               if (hba->msi_enabled)
+                       pci_disable_msi(pdev);
+       }
+       return status;
+}
+
+static void stex_free_irq(struct st_hba *hba)
+{
+       struct pci_dev *pdev = hba->pdev;
+
+       free_irq(pdev->irq, hba);
+       if (hba->msi_enabled)
+               pci_disable_msi(pdev);
+}
+
 static int __devinit
 stex_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -1125,7 +1163,7 @@ stex_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        hba->host = host;
        hba->pdev = pdev;
 
-       err = request_irq(pdev->irq, stex_intr, IRQF_SHARED, DRV_NAME, hba);
+       err = stex_request_irq(hba);
        if (err) {
                printk(KERN_ERR DRV_NAME "(%s): request irq failed\n",
                        pci_name(pdev));
@@ -1157,7 +1195,7 @@ stex_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        return 0;
 
 out_free_irq:
-       free_irq(pdev->irq, hba);
+       stex_free_irq(hba);
 out_pci_free:
        dma_free_coherent(&pdev->dev, hba->dma_size,
                          hba->dma_mem, hba->dma_handle);
@@ -1216,7 +1254,7 @@ static void stex_hba_stop(struct st_hba *hba)
 
 static void stex_hba_free(struct st_hba *hba)
 {
-       free_irq(hba->pdev->irq, hba);
+       stex_free_irq(hba);
 
        iounmap(hba->mmio_base);