+ * ipr_test_intr - Handle the interrupt generated in ipr_test_msi().
+ * @pdev: PCI device struct
+ *
+ * Description: Simply set the msi_received flag to 1 indicating that
+ * Message Signaled Interrupts are supported.
+ *
+ * Return value:
+ * 0 on success / non-zero on failure
+ **/
+static irqreturn_t __devinit ipr_test_intr(int irq, void *devp)
+{
+ struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)devp;
+ unsigned long lock_flags = 0;
+ irqreturn_t rc = IRQ_HANDLED;
+
+ spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+
+ ioa_cfg->msi_received = 1;
+ wake_up(&ioa_cfg->msi_wait_q);
+
+ spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+ return rc;
+}
+
+/**
+ * ipr_test_msi - Test for Message Signaled Interrupt (MSI) support.
+ * @pdev: PCI device struct
+ *
+ * Description: The return value from pci_enable_msi() can not always be
+ * trusted. This routine sets up and initiates a test interrupt to determine
+ * if the interrupt is received via the ipr_test_intr() service routine.
+ * If the tests fails, the driver will fall back to LSI.
+ *
+ * Return value:
+ * 0 on success / non-zero on failure
+ **/
+static int __devinit ipr_test_msi(struct ipr_ioa_cfg *ioa_cfg,
+ struct pci_dev *pdev)
+{
+ int rc;
+ volatile u32 int_reg;
+ unsigned long lock_flags = 0;
+
+ ENTER;
+
+ spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+ init_waitqueue_head(&ioa_cfg->msi_wait_q);
+ ioa_cfg->msi_received = 0;
+ ipr_mask_and_clear_interrupts(ioa_cfg, ~IPR_PCII_IOA_TRANS_TO_OPER);
+ writel(IPR_PCII_IO_DEBUG_ACKNOWLEDGE, ioa_cfg->regs.clr_interrupt_mask_reg);
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_mask_reg);
+ spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+
+ rc = request_irq(pdev->irq, ipr_test_intr, 0, IPR_NAME, ioa_cfg);
+ if (rc) {
+ dev_err(&pdev->dev, "Can not assign irq %d\n", pdev->irq);
+ return rc;
+ } else if (ipr_debug)
+ dev_info(&pdev->dev, "IRQ assigned: %d\n", pdev->irq);
+
+ writel(IPR_PCII_IO_DEBUG_ACKNOWLEDGE, ioa_cfg->regs.sense_interrupt_reg);
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_reg);
+ wait_event_timeout(ioa_cfg->msi_wait_q, ioa_cfg->msi_received, HZ);
+ ipr_mask_and_clear_interrupts(ioa_cfg, ~IPR_PCII_IOA_TRANS_TO_OPER);
+
+ spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+ if (!ioa_cfg->msi_received) {
+ /* MSI test failed */
+ dev_info(&pdev->dev, "MSI test failed. Falling back to LSI.\n");
+ rc = -EOPNOTSUPP;
+ } else if (ipr_debug)
+ dev_info(&pdev->dev, "MSI test succeeded.\n");
+
+ spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+
+ free_irq(pdev->irq, ioa_cfg);
+
+ LEAVE;
+
+ return rc;
+}
+
+/**