[igt-dev] [PATCH i-g-t] tests/i915/i915_hangman: add DG2 wa for hang subtest

[Kamil Konieczny]

DG2 requires a workaround that prevents context switches on CCS when
RCS is not idle. That breaks the hangman test because a hang on RCS
means CCS cannot switch. Thus, the well behaved background task on CCS
is seen as hanging and thus the test fails. The same problem is seen
on RCS when CCS is hang, so do not use the other one when causing hang.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5884
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
Signed-off-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>
---
 tests/i915/i915_hangman.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/i915/i915_hangman.c b/tests/i915/i915_hangman.c
index 687dee14..9e244a10 100644
--- a/tests/i915/i915_hangman.c
+++ b/tests/i915/i915_hangman.c
@@ -304,11 +304,17 @@ test_engine_hang(const intel_ctx_t *ctx,
 	igt_spin_t *spin, *next;
 	IGT_LIST_HEAD(list);
 	uint64_t ahnd = get_reloc_ahnd(device, ctx->id), ahndN;
+	int skip_class = -1;
 	int num_ctx;
 
 	igt_skip_on(flags & IGT_SPIN_INVALID_CS &&
 		    gem_engine_has_cmdparser(device, &ctx->cfg, e->flags));
 
+	/* Wa_14014494547:DG2 hang on RCS means CCS cannot switch */
+	if (IS_DG2(intel_get_drm_devid(device)))
+		skip_class = e->class == I915_ENGINE_CLASS_RENDER ? I915_ENGINE_CLASS_COMPUTE :
+					 I915_ENGINE_CLASS_RENDER;
+
 	/*
 	 * Fill all engines with background load.
 	 * This verifies that independent engines are unaffected and gives
@@ -317,6 +323,9 @@ test_engine_hang(const intel_ctx_t *ctx,
 	 */
 	num_ctx = 0;
 	for_each_ctx_engine(device, ctx, other) {
+		if (other->class == skip_class)
+			continue;
+
 		local_ctx[num_ctx] = intel_ctx_create(device, &ctx->cfg);
 		context_unban(device, local_ctx[num_ctx]->id);
 		ahndN = get_reloc_ahnd(device, local_ctx[num_ctx]->id);
-- 
2.34.1