pci 桥不转发VGA 地址

Question

我的vga显卡连接在一个桥后面
bus0---bridge0---bus1---VGA device
文件 drivers/gpu/vga/ vgaarb.c
该怎么处理啊？
往pci-pci bridge 写寄存器 PCI_BRIDGE_CONTROL ： PCI_BRIDGE_CTL_VGA
写入失败 有什么好方法呢？？

/* Check if VGA cycles can get down to us */
bus = pdev->bus;
while (bus) {
bridge = bus->self;
if (bridge) {
u16 l;

                    pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
                    if (!(l & PCI_BRIDGE_CTL_VGA)) {
                            vgadev->owns = 0;
                            break;
                    }
            }
            bus = bus->parent;
    }

如果不被break就好

Answer 1

http://blog.csdn.net/hjmhz/article/details/51756349