4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Paulo Zanoni <[email protected]> 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 <[email protected]> Signed-off-by: Paulo Zanoni <[email protected]> Acked-by: Chris Wilson <[email protected]> Reviewed-by: Daniel Vetter <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] (cherry picked from commit d43537610470d8829ebd17cd7842f47176e35ebd) Signed-off-by: Jani Nikula <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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);
