| From 6ba0566cf2afcdb17bff882e3a95cbbcb22c4a83 Mon Sep 17 00:00:00 2001 |
| From: Paulo Zanoni <paulo.r.zanoni@intel.com> |
| Date: Wed, 14 Dec 2016 12:55:37 -0200 |
| Subject: drm/i915: skip the first 4k of stolen memory on everything >= gen8 |
| |
| From: Paulo Zanoni <paulo.r.zanoni@intel.com> |
| |
| commit 6ba0566cf2afcdb17bff882e3a95cbbcb22c4a83 upstream. |
| |
| BSpec got updated and this workaround is now listed as standard |
| required programming for all subsequent projects. This is confirmed to |
| fix Skylake screen flickering issues (probably caused by the fact that |
| we initialized a ring in the first page of stolen, but I didn't 100% |
| confirm this theory). |
| |
| v2: this is the patch that fixes the screen flickering, document it. |
| |
| Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94605 |
| Tested-by: Dominik Klementowski <dominik232@gmail.com> |
| Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> |
| Acked-by: Chris Wilson <chris@chris-wilson.co.uk> |
| Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
| Link: http://patchwork.freedesktop.org/patch/msgid/1481727338-9901-1-git-send-email-paulo.r.zanoni@intel.com |
| (cherry picked from commit d43537610470d8829ebd17cd7842f47176e35ebd) |
| Signed-off-by: Jani Nikula <jani.nikula@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/i915/i915_gem_stolen.c | 5 ++--- |
| 1 file changed, 2 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/gpu/drm/i915/i915_gem_stolen.c |
| +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c |
| @@ -55,10 +55,9 @@ int i915_gem_stolen_insert_node_in_range |
| return -ENODEV; |
| |
| /* See the comment at the drm_mm_init() call for more about this check. |
| - * WaSkipStolenMemoryFirstPage:bdw,chv,kbl (incomplete) |
| + * WaSkipStolenMemoryFirstPage:bdw+ (incomplete) |
| */ |
| - if (start < 4096 && (IS_GEN8(dev_priv) || |
| - IS_KBL_REVID(dev_priv, 0, KBL_REVID_A0))) |
| + if (start < 4096 && INTEL_GEN(dev_priv) >= 8) |
| start = 4096; |
| |
| mutex_lock(&dev_priv->mm.stolen_lock); |
