[Intel-gfx] [bug report] drm/i915/selftests: Teach igt_gpu_fill_dw() to take intel_context

[Chris Wilson]

Quoting Dan Carpenter (2019-08-27 10:40:16)
> Hello Chris Wilson,
> 
> The patch 75b974a859e5: "drm/i915/selftests: Teach igt_gpu_fill_dw()
> to take intel_context" from Aug 24, 2019, leads to the following
> static checker warning:
> 
>         drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c:402 igt_ctx_exec()
>         error: 'ce' dereferencing possible ERR_PTR()
> 
> drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
>    388                  dw = 0;
>    389                  while (!time_after(jiffies, end_time)) {
>    390                          struct i915_gem_context *ctx;
>    391                          struct intel_context *ce;
>    392  
>    393                          ctx = live_context(i915, file);
>    394                          if (IS_ERR(ctx)) {
>    395                                  err = PTR_ERR(ctx);
>    396                                  goto out_unlock;
>    397                          }
>    398  
>    399                          ce = i915_gem_context_get_engine(ctx, engine->legacy_idx);
>                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> New assignment.  Smatch thinks it can be ERR_PTR(-EINVAL)

It can't be from successful construction of the live_context().

GEM_BUG_ON(IS_ERR(ce)) I guess.
-Chris