1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/gpu/drm/bochs/bochs_hw.c b/drivers/gpu/drm/bochs/bochs_hw.c
index e8b1dacc4911..460389702d31 100644
--- a/drivers/gpu/drm/bochs/bochs_hw.c
+++ b/drivers/gpu/drm/bochs/bochs_hw.c
@@ -51,7 +51,7 @@ int bochs_hw_init(struct drm_device *dev, uint32_t flags)
 {
         struct bochs_device *bochs = dev->dev_private;
         struct pci_dev *pdev = dev->pdev;
-        unsigned long addr, size, mem, ioaddr, iosize;
+        unsigned long addr, size, mem, ioaddr, iosize, qext_size;
         u16 id;
 
         if (pdev->resource[2].flags & IORESOURCE_MEM) {
@@ -115,6 +115,24 @@ int bochs_hw_init(struct drm_device *dev, uint32_t flags)
                  size / 1024, addr,
                  bochs->ioports ? "ioports" : "mmio",
                  ioaddr);
+
+        if (bochs->mmio && pdev->revision >= 2) {
+                qext_size = readl(bochs->mmio + 0x600);
+                if (qext_size < 4 || qext_size > iosize)
+                        goto noext;
+                DRM_DEBUG("Found qemu ext regs, size %ld\n", qext_size);
+                if (qext_size >= 8) {
+#ifdef __BIG_ENDIAN
+                        writel(0xbebebebe, bochs->mmio + 0x604);
+#else
+                        writel(0x1e1e1e1e, bochs->mmio + 0x604);
+#endif
+                        DRM_DEBUG("  qext endian: 0x%x\n",
+                                  readl(bochs->mmio + 0x604));
+                }
+        }
+
+noext:
         return 0;
 }