From 91f4228960adb6583a33af310912163469f49da7 Mon Sep 17 00:00:00 2001 From: Fei Yang Date: Wed, 15 Mar 2023 11:08:00 -0700 Subject: [PATCH] drm/i915/selftests: keep same cache settings as timeline On MTL, objects allocated through i915_gem_object_create_internal() are mapped as uncached in GPU by default because HAS_LLC is false. However in the live_hwsp_read selftest these watcher objects are mapped as WB on CPU side. The conseqence is that the updates done by the GPU are not immediately visible to CPU, thus the selftest is randomly failing due to the stale data in CPU cache. Solution can be either setting WC for CPU + UC for GPU, or WB for CPU + 1-way coherent WB for GPU. To keep the consistency, let's simply inherit the same cache settings from the timeline, which is WB for CPU + 1-way coherent WB for GPU, because this test is supposed to emulate the behavior of the timeline anyway. Signed-off-by: Fei Yang Reviewed-by: Matt Roper Signed-off-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20230315180800.2632766-1-fei.yang@intel.com --- drivers/gpu/drm/i915/gt/selftest_timeline.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c b/drivers/gpu/drm/i915/gt/selftest_timeline.c index 522d019..9f536c2 100644 --- a/drivers/gpu/drm/i915/gt/selftest_timeline.c +++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c @@ -825,7 +825,8 @@ static bool cmp_gte(u32 a, u32 b) return a >= b; } -static int setup_watcher(struct hwsp_watcher *w, struct intel_gt *gt) +static int setup_watcher(struct hwsp_watcher *w, struct intel_gt *gt, + struct intel_timeline *tl) { struct drm_i915_gem_object *obj; struct i915_vma *vma; @@ -834,7 +835,10 @@ static int setup_watcher(struct hwsp_watcher *w, struct intel_gt *gt) if (IS_ERR(obj)) return PTR_ERR(obj); - w->map = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB); + /* keep the same cache settings as timeline */ + i915_gem_object_set_cache_coherency(obj, tl->hwsp_ggtt->obj->cache_level); + w->map = i915_gem_object_pin_map_unlocked(obj, + page_unmask_bits(tl->hwsp_ggtt->obj->mm.mapping)); if (IS_ERR(w->map)) { i915_gem_object_put(obj); return PTR_ERR(w->map); @@ -1004,8 +1008,10 @@ static int live_hwsp_read(void *arg) if (!tl->has_initial_breadcrumb) goto out_free; + selftest_tl_pin(tl); + for (i = 0; i < ARRAY_SIZE(watcher); i++) { - err = setup_watcher(&watcher[i], gt); + err = setup_watcher(&watcher[i], gt, tl); if (err) goto out; } @@ -1160,6 +1166,8 @@ out: for (i = 0; i < ARRAY_SIZE(watcher); i++) cleanup_watcher(&watcher[i]); + intel_timeline_unpin(tl); + if (igt_flush_test(gt->i915)) err = -EIO; -- 2.7.4