drm/i915/selftests: Force a failed engine reset

Inject a fault into the engine reset and check that the outstanding
requests are completed despite the failed reset.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210113205049.22565-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
index ffc6eab..460c3e9 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
+++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
@@ -540,6 +540,149 @@ static int igt_reset_nop_engine(void *arg)
        return 0;
 }
 
+static void force_reset_timeout(struct intel_engine_cs *engine)
+{
+       engine->reset_timeout.probability = 999;
+       atomic_set(&engine->reset_timeout.times, -1);
+}
+
+static void cancel_reset_timeout(struct intel_engine_cs *engine)
+{
+       memset(&engine->reset_timeout, 0, sizeof(engine->reset_timeout));
+}
+
+static int igt_reset_fail_engine(void *arg)
+{
+       struct intel_gt *gt = arg;
+       struct intel_engine_cs *engine;
+       enum intel_engine_id id;
+
+       /* Check that we can recover from engine-reset failues */
+
+       if (!intel_has_reset_engine(gt))
+               return 0;
+
+       for_each_engine(engine, gt, id) {
+               unsigned int count;
+               struct intel_context *ce;
+               IGT_TIMEOUT(end_time);
+               int err;
+
+               ce = intel_context_create(engine);
+               if (IS_ERR(ce))
+                       return PTR_ERR(ce);
+
+               st_engine_heartbeat_disable(engine);
+               set_bit(I915_RESET_ENGINE + id, &gt->reset.flags);
+
+               force_reset_timeout(engine);
+               err = intel_engine_reset(engine, NULL);
+               cancel_reset_timeout(engine);
+               if (err == 0) /* timeouts only generated on gen8+ */
+                       goto skip;
+
+               count = 0;
+               do {
+                       struct i915_request *last = NULL;
+                       int i;
+
+                       if (!wait_for_idle(engine)) {
+                               pr_err("%s failed to idle before reset\n",
+                                      engine->name);
+                               err = -EIO;
+                               break;
+                       }
+
+                       for (i = 0; i < count % 15; i++) {
+                               struct i915_request *rq;
+
+                               rq = intel_context_create_request(ce);
+                               if (IS_ERR(rq)) {
+                                       struct drm_printer p =
+                                               drm_info_printer(gt->i915->drm.dev);
+                                       intel_engine_dump(engine, &p,
+                                                         "%s(%s): failed to submit request\n",
+                                                         __func__,
+                                                         engine->name);
+
+                                       GEM_TRACE("%s(%s): failed to submit request\n",
+                                                 __func__,
+                                                 engine->name);
+                                       GEM_TRACE_DUMP();
+
+                                       intel_gt_set_wedged(gt);
+                                       if (last)
+                                               i915_request_put(last);
+
+                                       err = PTR_ERR(rq);
+                                       goto out;
+                               }
+
+                               if (last)
+                                       i915_request_put(last);
+                               last = i915_request_get(rq);
+                               i915_request_add(rq);
+                       }
+
+                       if (count & 1) {
+                               err = intel_engine_reset(engine, NULL);
+                               if (err) {
+                                       GEM_TRACE_ERR("intel_engine_reset(%s) failed, err:%d\n",
+                                                     engine->name, err);
+                                       GEM_TRACE_DUMP();
+                                       i915_request_put(last);
+                                       break;
+                               }
+                       } else {
+                               force_reset_timeout(engine);
+                               err = intel_engine_reset(engine, NULL);
+                               cancel_reset_timeout(engine);
+                               if (err != -ETIMEDOUT) {
+                                       pr_err("intel_engine_reset(%s) did not fail, err:%d\n",
+                                              engine->name, err);
+                                       i915_request_put(last);
+                                       break;
+                               }
+                       }
+
+                       err = 0;
+                       if (last) {
+                               if (i915_request_wait(last, 0, HZ / 2) < 0) {
+                                       struct drm_printer p =
+                                               drm_info_printer(gt->i915->drm.dev);
+
+                                       intel_engine_dump(engine, &p,
+                                                         "%s(%s): failed to complete request\n",
+                                                         __func__,
+                                                         engine->name);
+
+                                       GEM_TRACE("%s(%s): failed to complete request\n",
+                                                 __func__,
+                                                 engine->name);
+                                       GEM_TRACE_DUMP();
+
+                                       err = -EIO;
+                               }
+                               i915_request_put(last);
+                       }
+                       count++;
+               } while (err == 0 && time_before(jiffies, end_time));
+out:
+               pr_info("%s(%s): %d resets\n", __func__, engine->name, count);
+skip:
+               clear_bit(I915_RESET_ENGINE + id, &gt->reset.flags);
+               st_engine_heartbeat_enable(engine);
+               intel_context_put(ce);
+
+               if (igt_flush_test(gt->i915))
+                       err = -EIO;
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
 static int __igt_reset_engine(struct intel_gt *gt, bool active)
 {
        struct i915_gpu_error *global = &gt->i915->gpu_error;
@@ -1694,6 +1837,7 @@ int intel_hangcheck_live_selftests(struct drm_i915_private *i915)
                SUBTEST(igt_reset_nop_engine),
                SUBTEST(igt_reset_idle_engine),
                SUBTEST(igt_reset_active_engine),
+               SUBTEST(igt_reset_fail_engine),
                SUBTEST(igt_reset_engines),
                SUBTEST(igt_reset_engines_atomic),
                SUBTEST(igt_reset_queue),