drm/mgag200: Add module parameter to pin all buffers at offset 0

[linux-2.6-microblaze.git] / drivers / gpu / drm / mgag200 / mgag200_drv.c

diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
index ee4fb9c..7a5bad2 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_drv.c
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -27,6 +27,10 @@ int mgag200_modeset = -1;
 MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
 module_param_named(modeset, mgag200_modeset, int, 0400);
 
+int mgag200_hw_bug_no_startadd = -1;
+MODULE_PARM_DESC(modeset, "HW does not interpret scanout-buffer start address correctly");
+module_param_named(hw_bug_no_startadd, mgag200_hw_bug_no_startadd, int, 0400);
+
 static struct drm_driver driver;
 
 static const struct pci_device_id pciidlist[] = {
@@ -97,6 +101,16 @@ DEFINE_DRM_GEM_FOPS(mgag200_driver_fops);
 
 static bool mgag200_pin_bo_at_0(const struct mga_device *mdev)
 {
+       if (mgag200_hw_bug_no_startadd > 0) {
+               DRM_WARN_ONCE("Option hw_bug_no_startradd is enabled. Please "
+                             "report the output of 'lspci -vvnn' to "
+                             "<dri-devel@lists.freedesktop.org> if this "
+                             "option is required to make mgag200 work "
+                             "correctly on your system.\n");
+               return true;
+       } else if (!mgag200_hw_bug_no_startadd) {
+               return false;
+       }
        return mdev->flags & MGAG200_FLAG_HW_BUG_NO_STARTADD;
 }