static void pci_fixup_video()

in pci/fixup.c [30:78]

• 35 lines of code
• 10 McCabe index (conditional complexity)

static void pci_fixup_video(struct pci_dev *pdev)
{
	struct pci_dev *bridge;
	struct pci_bus *bus;
	u16 config;
	struct resource *res;

	if (is_uv_system())
		return;
	/* Maybe, this machine supports legacy memory map. */

	/* Is VGA routed to us? */
	bus = pdev->bus;
	while (bus) {
		bridge = bus->self;

		/*
		 * From information provided by
		 * "David Miller" <davem@davemloft.net>
		 * The bridge control register is valid for PCI header
		 * type BRIDGE, or CARDBUS. Host to PCI controllers use
		 * PCI header type NORMAL.
		 */
		if (bridge && (pci_is_bridge(bridge))) {
			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
						&config);
			if (!(config & PCI_BRIDGE_CTL_VGA))
				return;
		}
		bus = bus->parent;
	}
	if (!vga_default_device() || pdev == vga_default_device()) {
		pci_read_config_word(pdev, PCI_COMMAND, &config);
		if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
			res = &pdev->resource[PCI_ROM_RESOURCE];

			pci_disable_rom(pdev);
			if (res->parent)
				release_resource(res);

			res->start = 0xC0000;
			res->end = res->start + 0x20000 - 1;
			res->flags = IORESOURCE_MEM | IORESOURCE_ROM_SHADOW |
				     IORESOURCE_PCI_FIXED;
			dev_info(&pdev->dev, "Video device with shadowed ROM at %pR\n",
				 res);
		}
	}
}