drm/i915/selftests: Hold request reference over waits

Take a reference on the request before submitting it to the HW and then
waiting on it for selftest_workarounds. Once submitted, the request may
be freed by a background worker, unless we take an extra reference for
ourselves.

References: https://bugs.freedesktop.org/show_bug.cgi?id=111926
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/20191009061759.3189-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
index 74952bd..1048be6 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -33,6 +33,30 @@ struct wa_lists {
        } engine[I915_NUM_ENGINES];
 };
 
+static int request_add_sync(struct i915_request *rq, int err)
+{
+       i915_request_get(rq);
+       i915_request_add(rq);
+       if (i915_request_wait(rq, 0, HZ / 5) < 0)
+               err = -EIO;
+       i915_request_put(rq);
+
+       return err;
+}
+
+static int request_add_spin(struct i915_request *rq, struct igt_spinner *spin)
+{
+       int err = 0;
+
+       i915_request_get(rq);
+       i915_request_add(rq);
+       if (spin && !igt_wait_for_spinner(spin, rq))
+               err = -ETIMEDOUT;
+       i915_request_put(rq);
+
+       return err;
+}
+
 static void
 reference_lists_init(struct drm_i915_private *i915, struct wa_lists *lists)
 {
@@ -243,7 +267,6 @@ switch_to_scratch_context(struct intel_engine_cs *engine,
        struct i915_gem_context *ctx;
        struct intel_context *ce;
        struct i915_request *rq;
-       intel_wakeref_t wakeref;
        int err = 0;
 
        ctx = kernel_context(engine->i915);
@@ -255,9 +278,7 @@ switch_to_scratch_context(struct intel_engine_cs *engine,
        ce = i915_gem_context_get_engine(ctx, engine->legacy_idx);
        GEM_BUG_ON(IS_ERR(ce));
 
-       rq = ERR_PTR(-ENODEV);
-       with_intel_runtime_pm(engine->uncore->rpm, wakeref)
-               rq = igt_spinner_create_request(spin, ce, MI_NOOP);
+       rq = igt_spinner_create_request(spin, ce, MI_NOOP);
 
        intel_context_put(ce);
 
@@ -267,13 +288,7 @@ switch_to_scratch_context(struct intel_engine_cs *engine,
                goto err;
        }
 
-       i915_request_add(rq);
-
-       if (spin && !igt_wait_for_spinner(spin, rq)) {
-               pr_err("Spinner failed to start\n");
-               err = -ETIMEDOUT;
-       }
-
+       err = request_add_spin(rq, spin);
 err:
        if (err && spin)
                igt_spinner_end(spin);
@@ -586,15 +601,11 @@ static int check_dirty_whitelist(struct i915_gem_context *ctx,
                        goto err_request;
 
 err_request:
-               i915_request_add(rq);
-               if (err)
-                       goto out_batch;
-
-               if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+               err = request_add_sync(rq, err);
+               if (err) {
                        pr_err("%s: Futzing %x timedout; cancelling test\n",
                               engine->name, reg);
                        intel_gt_set_wedged(&ctx->i915->gt);
-                       err = -EIO;
                        goto out_batch;
                }
 
@@ -697,7 +708,6 @@ static int live_dirty_whitelist(void *arg)
        struct intel_engine_cs *engine;
        struct i915_gem_context *ctx;
        enum intel_engine_id id;
-       intel_wakeref_t wakeref;
        struct drm_file *file;
        int err = 0;
 
@@ -706,13 +716,9 @@ static int live_dirty_whitelist(void *arg)
        if (INTEL_GEN(i915) < 7) /* minimum requirement for LRI, SRM, LRM */
                return 0;
 
-       wakeref = intel_runtime_pm_get(&i915->runtime_pm);
-
        file = mock_file(i915);
-       if (IS_ERR(file)) {
-               err = PTR_ERR(file);
-               goto out_rpm;
-       }
+       if (IS_ERR(file))
+               return PTR_ERR(file);
 
        ctx = live_context(i915, file);
        if (IS_ERR(ctx)) {
@@ -731,8 +737,6 @@ static int live_dirty_whitelist(void *arg)
 
 out_file:
        mock_file_free(i915, file);
-out_rpm:
-       intel_runtime_pm_put(&i915->runtime_pm, wakeref);
        return err;
 }
 
@@ -807,12 +811,7 @@ static int read_whitelisted_registers(struct i915_gem_context *ctx,
        intel_ring_advance(rq, cs);
 
 err_req:
-       i915_request_add(rq);
-
-       if (i915_request_wait(rq, 0, HZ / 5) < 0)
-               err = -EIO;
-
-       return err;
+       return request_add_sync(rq, err);
 }
 
 static int scrub_whitelisted_registers(struct i915_gem_context *ctx,
@@ -872,9 +871,7 @@ static int scrub_whitelisted_registers(struct i915_gem_context *ctx,
        err = engine->emit_bb_start(rq, batch->node.start, 0, 0);
 
 err_request:
-       i915_request_add(rq);
-       if (i915_request_wait(rq, 0, HZ / 5) < 0)
-               err = -EIO;
+       err = request_add_sync(rq, err);
 
 err_unpin:
        i915_gem_object_unpin_map(batch->obj);
@@ -1229,12 +1226,10 @@ live_engine_reset_workarounds(void *arg)
                        goto err;
                }
 
-               i915_request_add(rq);
-
-               if (!igt_wait_for_spinner(&spin, rq)) {
+               ret = request_add_spin(rq, &spin);
+               if (ret) {
                        pr_err("Spinner failed to start\n");
                        igt_spinner_fini(&spin);
-                       ret = -ETIMEDOUT;
                        goto err;
                }