+/* Check if INTX works to control irq's.
+ * Set's INTX_DISABLE flag and reads it back
+ */
+static bool pci_intx_mask_supported(struct pci_dev *dev)
+{
+ bool mask_supported = false;
+ uint16_t orig, new
+
+ pci_block_user_cfg_access(dev);
+ pci_read_config_word(pdev, PCI_COMMAND, &orig);
+ pci_write_config_word(dev, PCI_COMMAND,
+ orig ^ PCI_COMMAND_INTX_DISABLE);
+ pci_read_config_word(dev, PCI_COMMAND, &new);
+
+ if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
+ dev_err(&dev->dev, "Command register changed from "
+ "0x%x to 0x%x: driver or hardware bug?\n", orig, new);
+ } else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
+ mask_supported = true;
+ pci_write_config_word(dev, PCI_COMMAND, orig);
+ }
+ pci_unblock_user_cfg_access(dev);