Some IVB machines seem to need non-MT forcewake. Using MT forcewake on such machines result in broken or blank screens.
Signed-off-by: Takashi Iwai <[email protected]> --- The commit 36ec8f877481449bdfa072e6adf2060869e2b970 triggered a regression on my test IVY laptops. Instead of reverting the commit, I cooked a bit to make fitting only for IS_IVYBRIDGE(). drivers/gpu/drm/i915/intel_pm.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 0cbc0e6..944911e 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4239,9 +4239,36 @@ 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 (IS_IVYBRIDGE(dev) || IS_HASWELL(dev)) { + } else if (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_IVYBRIDGE(dev)) { + /* IVB configs may use multi-threaded forcewake */ + 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; + } else { + dev_priv->gt.force_wake_get = __gen6_gt_force_wake_get; + dev_priv->gt.force_wake_put = __gen6_gt_force_wake_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; -- 1.8.0 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
