drm/vmwgfx: Request SVGA version 2 and bail if not found

This fixes the driver not loading on older versions of VMware.

Signed-off-by: Peter Hanzel <hanzelpeter@gmail.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index f47ff2c..a6e8f68 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -209,6 +209,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 {
        struct vmw_private *dev_priv;
        int ret;
+       uint32_t svga_id;
 
        dev_priv = kzalloc(sizeof(*dev_priv), GFP_KERNEL);
        if (unlikely(dev_priv == NULL)) {
@@ -239,6 +240,16 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
        dev_priv->mmio_start = pci_resource_start(dev->pdev, 2);
 
        mutex_lock(&dev_priv->hw_mutex);
+
+       vmw_write(dev_priv, SVGA_REG_ID, SVGA_ID_2);
+       svga_id = vmw_read(dev_priv, SVGA_REG_ID);
+       if (svga_id != SVGA_ID_2) {
+               ret = -ENOSYS;
+               DRM_ERROR("Unsuported SVGA ID 0x%x\n", svga_id);
+               mutex_unlock(&dev_priv->hw_mutex);
+               goto out_err0;
+       }
+
        dev_priv->capabilities = vmw_read(dev_priv, SVGA_REG_CAPABILITIES);
 
        if (dev_priv->capabilities & SVGA_CAP_GMR) {