From: Chris Wilson Date: Wed, 31 May 2017 19:05:14 +0000 (+0100) Subject: drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally X-Git-Tag: v4.12-rc5~25^2~1^2~5 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=d90c98905afd00c15d5d255d845b646a37173ce9;p=linux.git drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally Commit 7c3f86b6dc51 ("drm/i915: Invalidate the guc ggtt TLB upon insertion") added the restoration of the invalidation routine after the GuC was disabled, but missed that the GuC was unconditionally disabled when not used. This then overwrites the invalidate routine for the older chipsets, causing havoc and breaking resume as the most obvious victim. We place the guard inside i915_ggtt_disable_guc() to be backport friendly (the bug was introduced into v4.11) but it would be preferred to be in more control over when this was guard (i.e. do not try and teardown the data structures before we have enabled them). That should be true with the reorganisation of the guc loaders. Reported-by: Ville Syrjälä Signed-off-by: Chris Wilson Fixes: 7c3f86b6dc51 ("drm/i915: Invalidate the guc ggtt TLB upon insertion") Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Cc: Oscar Mateo Cc: Daniele Ceraolo Spurio Cc: Michal Wajdeczko Cc: Arkadiusz Hiler Cc: # v4.11+ Link: http://patchwork.freedesktop.org/patch/msgid/20170531190514.3691-1-chris@chris-wilson.co.uk Reviewed-by: Michel Thierry (cherry picked from commit cb60606d835ca8b2f744835116bcabe64ce88849) Signed-off-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index db89843bdd46..f1989b8792dd 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -3100,7 +3100,8 @@ void i915_ggtt_enable_guc(struct drm_i915_private *i915) void i915_ggtt_disable_guc(struct drm_i915_private *i915) { - i915->ggtt.invalidate = gen6_ggtt_invalidate; + if (i915->ggtt.invalidate == guc_ggtt_invalidate) + i915->ggtt.invalidate = gen6_ggtt_invalidate; } void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)