[PATCH] drm/i915/gem: update outdated comment

[PATCH] drm/i915/gem: update outdated comment

[Kexin Sun]

The function set_engines() was removed in commit d9d29c747df8
("drm/i915/gem: Don't allow changing the engine set on running
contexts (v3)").

However, concurrent code paths such as i915_gem_context_lock_engines()
still access ctx->engines under engines_mutex (e.g. from execbuf
throttle), so the lock in context_close() remains necessary to
serialize the engine teardown against these concurrent readers.

So, remove the outdated reference to set_engines(), but preserve the
serialization reminder.

Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 6ac0f23570f3..958e3c822948 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1516,7 +1516,7 @@ static void context_close(struct i915_gem_context *ctx)
 {
 	struct i915_drm_client *client;
 
-	/* Flush any concurrent set_engines() */
+	/* Serialize against concurrent access to the context's engines */
 	mutex_lock(&ctx->engines_mutex);
 	unpin_engines(__context_engines_static(ctx));
 	engines_idle_release(ctx, rcu_replace_pointer(ctx->engines, NULL, 1));
-- 
2.25.1

Claude review: drm/i915/gem: update outdated comment

[Claude Code Review Bot]

Overall Series Review

Subject: drm/i915/gem: update outdated comment
Author: Kexin Sun <kexinsun@smail.nju.edu.cn>
Patches: 1
Reviewed: 2026-03-13T14:47:22.791586

---

This is a single-patch series that updates an outdated comment in the i915 GEM context code. The change is trivially correct and well-motivated. The old comment referenced `set_engines()`, a function removed in commit d9d29c747df8, while the mutex is still needed for serialization against other concurrent engine accessors like `i915_gem_context_lock_engines()`. The new comment is more general and accurate.

---
Generated by Claude Code Patch Reviewer

Claude review: drm/i915/gem: update outdated comment

[Claude Code Review Bot]

Patch Review

**Correctness:** The patch is correct.

- `set_engines()` is confirmed to no longer exist in `i915_gem_context.c`.
- The `engines_mutex` lock at line 1520 is still needed because `i915_gem_context_lock_engines()` (defined in `i915_gem_context.h:190`) and callers such as `i915_gem_throttle.c:61` access `ctx->engines` under this mutex concurrently.
- The replacement comment `/* Serialize against concurrent access to the context's engines */` accurately describes the purpose of the lock.

**Minor notes:**

1. The `Assisted-by: unnamed:deepseek-v3.2 coccinelle` tag is non-standard. Typically `Assisted-by` is not an established kernel tag (the recognized ones are things like `Suggested-by`, `Reported-by`, etc.). The maintainer may want the author to either drop this tag or use a more standard format. Additionally, listing "coccinelle" alongside an AI model name is confusing since Coccinelle is a separate tool — it's unclear what role each played in a comment-only change.

2. The commit message is well-written and provides good justification for why the lock is retained even though `set_engines()` is gone.

**Verdict:** Looks good to merge, modulo the non-standard tag. The code change itself is a clear improvement.

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Generated by Claude Code Patch Reviewer