misc: pci_endpoint_test: Skip IRQ tests if irq is out of range

The pci_endpoint_test tests the 32-bit MSI range. However, the device might
not have all vectors configured. For example, if msi_interrupts is 8 in the
ep function space or if the MSI Multiple Message Capable value is
configured as 4 (maximum 16 vectors).

In this case, do not attempt to run the test to avoid timeouts and directly
return the error value.

Signed-off-by: Christian Bruel <christian.bruel@foss.st.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20250804170916.3212221-2-christian.bruel@foss.st.com

Author: bruelc

drivers/misc/pci_endpoint_test.c

@@ -436,7 +436,11 @@ static int pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
 {
 	struct pci_dev *pdev = test->pdev;
 	u32 val;
-	int ret;
+	int irq;
+
+	irq = pci_irq_vector(pdev, msi_num - 1);
+	if (irq < 0)
+		return irq;
 
 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_TYPE,
 				 msix ? PCITEST_IRQ_TYPE_MSIX :
@@ -450,11 +454,7 @@ static int pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
 	if (!val)
 		return -ETIMEDOUT;
 
-	ret = pci_irq_vector(pdev, msi_num - 1);
-	if (ret < 0)
-		return ret;
-
-	if (ret != test->last_irq)
+	if (irq != test->last_irq)
 		return -EIO;
 
 	return 0;