drm/i915/perf: Initialise err to 0 before looping over ce->engines

Smatch warning that the loop may be empty causing us to check err before
it had been set. Ensure that it is initialised to 0, just in case.

v2: Refactor the inner loop for better scooping and clarity

Fixes: f02fec1f7de1 ("drm/i915/oa: Reconfigure contexts on the fly")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190726131458.8310-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index ab82ccba896bd52cdd08cb00151a65435ab5cbfa..d8941a791cd61579e97f417e46471f538e6fb720 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1792,6 +1792,38 @@ static int gen8_modify_self(struct intel_context *ce,
        return err;
 }
 
+static int gen8_configure_context(struct i915_gem_context *ctx,
+                                 struct flex *flex, unsigned int count)
+{
+       struct i915_gem_engines_iter it;
+       struct intel_context *ce;
+       int err = 0;
+
+       for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
+               GEM_BUG_ON(ce == ce->engine->kernel_context);
+
+               if (ce->engine->class != RENDER_CLASS)
+                       continue;
+
+               err = intel_context_lock_pinned(ce);
+               if (err)
+                       break;
+
+               flex->value = intel_sseu_make_rpcs(ctx->i915, &ce->sseu);
+
+               /* Otherwise OA settings will be set upon first use */
+               if (intel_context_is_pinned(ce))
+                       err = gen8_modify_context(ce, flex, count);
+
+               intel_context_unlock_pinned(ce);
+               if (err)
+                       break;
+       }
+       i915_gem_context_unlock_engines(ctx);
+
+       return err;
+}
+
 /*
  * Manages updating the per-context aspects of the OA stream
  * configuration across all contexts.
@@ -1846,7 +1878,6 @@ static int gen8_configure_all_contexts(struct drm_i915_private *i915,
        struct intel_engine_cs *engine;
        struct i915_gem_context *ctx;
        enum intel_engine_id id;
-       int err;
        int i;
 
        for (i = 2; i < ARRAY_SIZE(regs); i++)
@@ -1871,35 +1902,12 @@ static int gen8_configure_all_contexts(struct drm_i915_private *i915,
         * trapped behind the barrier.
         */
        list_for_each_entry(ctx, &i915->contexts.list, link) {
-               struct i915_gem_engines_iter it;
-               struct intel_context *ce;
+               int err;
 
                if (ctx == i915->kernel_context)
                        continue;
 
-               for_each_gem_engine(ce,
-                                   i915_gem_context_lock_engines(ctx),
-                                   it) {
-                       GEM_BUG_ON(ce == ce->engine->kernel_context);
-
-                       if (ce->engine->class != RENDER_CLASS)
-                               continue;
-
-                       err = intel_context_lock_pinned(ce);
-                       if (err)
-                               break;
-
-                       regs[0].value = intel_sseu_make_rpcs(i915, &ce->sseu);
-
-                       /* Otherwise OA settings will be set upon first use */
-                       if (intel_context_is_pinned(ce))
-                               err = gen8_modify_context(ce, regs, ARRAY_SIZE(regs));
-
-                       intel_context_unlock_pinned(ce);
-                       if (err)
-                               break;
-               }
-               i915_gem_context_unlock_engines(ctx);
+               err = gen8_configure_context(ctx, regs, ARRAY_SIZE(regs));
                if (err)
                        return err;
        }
@@ -1911,6 +1919,7 @@ static int gen8_configure_all_contexts(struct drm_i915_private *i915,
         */
        for_each_engine(engine, i915, id) {
                struct intel_context *ce = engine->kernel_context;
+               int err;
 
                if (engine->class != RENDER_CLASS)
                        continue;