static int __init efifb_set_system()

in efi/sysfb_efi.c [96:177]

• 69 lines of code
• 17 McCabe index (conditional complexity)

static int __init efifb_set_system(const struct dmi_system_id *id)
{
	struct efifb_dmi_info *info = id->driver_data;

	if (info->base == 0 && info->height == 0 && info->width == 0 &&
	    info->stride == 0)
		return 0;

	/* Trust the bootloader over the DMI tables */
	if (screen_info.lfb_base == 0) {
#if defined(CONFIG_PCI)
		struct pci_dev *dev = NULL;
		int found_bar = 0;
#endif
		if (info->base) {
			screen_info.lfb_base = choose_value(info->base,
				screen_info.lfb_base, OVERRIDE_BASE,
				info->flags);

#if defined(CONFIG_PCI)
			/* make sure that the address in the table is actually
			 * on a VGA device's PCI BAR */

			for_each_pci_dev(dev) {
				int i;
				if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
					continue;
				for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
					resource_size_t start, end;
					unsigned long flags;

					flags = pci_resource_flags(dev, i);
					if (!(flags & IORESOURCE_MEM))
						continue;

					if (flags & IORESOURCE_UNSET)
						continue;

					if (pci_resource_len(dev, i) == 0)
						continue;

					start = pci_resource_start(dev, i);
					end = pci_resource_end(dev, i);
					if (screen_info.lfb_base >= start &&
					    screen_info.lfb_base < end) {
						found_bar = 1;
						break;
					}
				}
			}
			if (!found_bar)
				screen_info.lfb_base = 0;
#endif
		}
	}
	if (screen_info.lfb_base) {
		screen_info.lfb_linelength = choose_value(info->stride,
			screen_info.lfb_linelength, OVERRIDE_STRIDE,
			info->flags);
		screen_info.lfb_width = choose_value(info->width,
			screen_info.lfb_width, OVERRIDE_WIDTH,
			info->flags);
		screen_info.lfb_height = choose_value(info->height,
			screen_info.lfb_height, OVERRIDE_HEIGHT,
			info->flags);
		if (screen_info.orig_video_isVGA == 0)
			screen_info.orig_video_isVGA = VIDEO_TYPE_EFI;
	} else {
		screen_info.lfb_linelength = 0;
		screen_info.lfb_width = 0;
		screen_info.lfb_height = 0;
		screen_info.orig_video_isVGA = 0;
		return 0;
	}

	printk(KERN_INFO "efifb: dmi detected %s - framebuffer at 0x%08x "
			 "(%dx%d, stride %d)\n", id->ident,
			 screen_info.lfb_base, screen_info.lfb_width,
			 screen_info.lfb_height, screen_info.lfb_linelength);

	return 1;
}