[Bug 99938] [BAT][GVT-d] timeout waiting for SBI to complete read transaction

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=99938

--- Comment #12 from XiongZhang <xiong.y.zhang at intel.com> ---
The issue is: "HAS_PCH_LPT_LP(dev_priv) ? SBI_GEN0 : SBI_DBUFF0" exist in
lpt_enable_clkout_dp() and lpt_disable_clkout_dp() function. 
  In GVT-d, PCH ISA bridge isn't passed through to guest, I915 could only
assume it is a LPT pch and couldn't identify whether it is a LPT_LP, LPT or
LPT_H PCH. So the above function will default read/write SBI_DBUFF0 register,
this is wrong if it is running on LPT_LP PCH.  

The following experiment could remove this error message, but it also break LPT
and LPT-H pch.
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8b807a9..0c295f1 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -135,6 +135,7 @@ static enum intel_pch intel_virt_detect_pch(struct
drm_i915_private *dev_priv)
                DRM_DEBUG_KMS("Assuming CouarPoint PCH\n");
        } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
                ret = PCH_LPT;
+               dev_priv->pch_id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
                DRM_DEBUG_KMS("Assuming LynxPoint PCH\n");
        } else if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) {
                ret = PCH_SPT;

Is there a method to identify LPT, LPT_LP or LPT_H from IGD itself, not from
PCH ISA bridge ?

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20170328/41f28f3c/attachment.html>