drm/i915: unconditionally use mt forcewake on hsw/ivb

Single-threaded forcewake was only used on some early pre-production
ivybridge machines, all the latest ones should use mt forcewake. And
we already assume this in other places of the code (e.g. DERRMR
support in the ddx, or the latest intel_gt_reset patch to reset any
lingering forcewake references left behind by the bios), so don't
bother here, too.

Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 2b3cddf5b7f7e23a3661663d1f3f72799d44d06e..568c98dc5b14ee22cf88b7f3c7a16c43c4fc1821 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4146,35 +4146,12 @@ void intel_gt_init(struct drm_device *dev)
        if (IS_VALLEYVIEW(dev)) {
                dev_priv->gt.force_wake_get = vlv_force_wake_get;
                dev_priv->gt.force_wake_put = vlv_force_wake_put;
-       } else if (INTEL_INFO(dev)->gen >= 6) {
+       } else if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev)) {
+               dev_priv->gt.force_wake_get = __gen6_gt_force_wake_mt_get;
+               dev_priv->gt.force_wake_put = __gen6_gt_force_wake_mt_put;
+       } else if (IS_GEN6(dev)) {
                dev_priv->gt.force_wake_get = __gen6_gt_force_wake_get;
                dev_priv->gt.force_wake_put = __gen6_gt_force_wake_put;
-
-               /* IVB configs may use multi-threaded forcewake */
-               if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev)) {
-                       u32 ecobus;
-
-                       /* A small trick here - if the bios hasn't configured
-                        * MT forcewake, and if the device is in RC6, then
-                        * force_wake_mt_get will not wake the device and the
-                        * ECOBUS read will return zero. Which will be
-                        * (correctly) interpreted by the test below as MT
-                        * forcewake being disabled.
-                        */
-                       mutex_lock(&dev->struct_mutex);
-                       __gen6_gt_force_wake_mt_get(dev_priv);
-                       ecobus = I915_READ_NOTRACE(ECOBUS);
-                       __gen6_gt_force_wake_mt_put(dev_priv);
-                       mutex_unlock(&dev->struct_mutex);
-
-                       if (ecobus & FORCEWAKE_MT_ENABLE) {
-                               DRM_DEBUG_KMS("Using MT version of forcewake\n");
-                               dev_priv->gt.force_wake_get =
-                                       __gen6_gt_force_wake_mt_get;
-                               dev_priv->gt.force_wake_put =
-                                       __gen6_gt_force_wake_mt_put;
-                       }
-               }
        }
 }