drm/i915: add prefault_disable module option

prefault is stll enabled by default which prevent most of pwrite/pread/reloc
from running slow path, in order to verify these slow pathes, prefault need
to be disabled.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
[danvet: Make checkpatch happy and bikeshed the module option help
text a bit.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b178a7ca1294..c34086ad8181 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -141,6 +141,11 @@ module_param_named(fastboot, i915_fastboot, bool, 0600);
 MODULE_PARM_DESC(fastboot, "Try to skip unnecessary mode sets at boot time "
                  "(default: false)");
 
+bool i915_prefault_disable __read_mostly;
+module_param_named(prefault_disable, i915_prefault_disable, bool, 0600);
+MODULE_PARM_DESC(prefault_disable,
+                "Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only.");
+
 static struct drm_driver driver;
 extern int intel_agp_enabled;