[Intel-gfx] [PATCH] agp/intel: Disable use of WC for GMM updates

[Intel-gfx] [PATCH] agp/intel: Disable use of WC for GMM updates

[Chris Wilson]

It appears that Ironlake is very sensitive to having its GGTT PTE
updates flushed in a timely manner and requires UC rather than WC for
all, and not just under VT'd.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/char/agp/intel-gtt.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 66a62d17a3f5..afe5e81bafac 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -565,35 +565,12 @@ static void intel_gtt_cleanup(void)
 	intel_gtt_teardown_scratch_page();
 }
 
-/* Certain Gen5 chipsets require require idling the GPU before
- * unmapping anything from the GTT when VT-d is enabled.
- */
-static inline int needs_ilk_vtd_wa(void)
-{
-#ifdef CONFIG_INTEL_IOMMU
-	const unsigned short gpu_devid = intel_private.pcidev->device;
-
-	/* Query intel_iommu to see if we need the workaround. Presumably that
-	 * was loaded first.
-	 */
-	if ((gpu_devid == PCI_DEVICE_ID_INTEL_IRONLAKE_D_IG ||
-	     gpu_devid == PCI_DEVICE_ID_INTEL_IRONLAKE_M_IG) &&
-	     intel_iommu_gfx_mapped)
-		return 1;
-#endif
-	return 0;
-}
-
 static bool intel_gtt_can_wc(void)
 {
 	if (INTEL_GTT_GEN <= 2)
 		return false;
 
-	if (INTEL_GTT_GEN >= 6)
-		return false;
-
-	/* Reports of major corruption with ILK vt'd enabled */
-	if (needs_ilk_vtd_wa())
+	if (INTEL_GTT_GEN >= 5)
 		return false;
 
 	return true;
-- 
2.20.1

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[Intel-gfx] ✗ Fi.CI.BAT: failure for agp/intel: Disable use of WC for GMM updates

[Patchwork]

== Series Details ==

Series: agp/intel: Disable use of WC for GMM updates
URL   : https://patchwork.freedesktop.org/series/75680/
State : failure

== Summary ==

CI Bug Log - changes from CI_DRM_8277 -> Patchwork_17255
====================================================

Summary
-------

  **FAILURE**

  Serious unknown changes coming with Patchwork_17255 absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_17255, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_17255/index.html

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_17255:

### IGT changes ###

#### Possible regressions ####

  * igt@i915_selftest@live@execlists:
    - fi-icl-dsi:         [PASS][1] -> [INCOMPLETE][2]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_8277/fi-icl-dsi/igt@i915_selftest@live@execlists.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_17255/fi-icl-dsi/igt@i915_selftest@live@execlists.html

  
Known issues
------------

  Here are the changes found in Patchwork_17255 that come from known issues:

### IGT changes ###

#### Possible fixes ####

  * igt@gem_exec_suspend@basic-s4-devices:
    - fi-tgl-y:           [FAIL][3] ([i915#1158]) -> [PASS][4]
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_8277/fi-tgl-y/igt@gem_exec_suspend@basic-s4-devices.html
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_17255/fi-tgl-y/igt@gem_exec_suspend@basic-s4-devices.html

  
  [i915#1158]: https://gitlab.freedesktop.org/drm/intel/issues/1158


Participating hosts (52 -> 47)
------------------------------

  Additional (1): fi-kbl-7560u 
  Missing    (6): fi-ilk-m540 fi-hsw-4200u fi-byt-squawks fi-bsw-cyan fi-byt-clapper fi-bdw-samus 


Build changes
-------------

  * CI: CI-20190529 -> None
  * Linux: CI_DRM_8277 -> Patchwork_17255

  CI-20190529: 20190529
  CI_DRM_8277: f7d56913e1668f3a269db391189a7888a4b22570 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_5581: ab0620e555119ec55f12ba9ab9e6e9246d407648 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_17255: a18804e368c8302a0e6c48e9025555c2bcf92e30 @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

a18804e368c8 agp/intel: Disable use of WC for GMM updates

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_17255/index.html
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