Re: [PATCH v2 04/14] drm/i915/gt: Open-code active timeline walk

[Andy Shevchenko]

On Tue, Jun 09, 2026 at 02:25:16PM +0800, Kaitao Cheng wrote:
> 
> A later change will make list_for_each_entry() cache the next element
> before entering the loop body. __intel_gt_unset_wedged() drops
> timelines->lock while waiting on a fence and then restarts the walk from
> the list head after the lock is reacquired.
> 
> Keep the loop open-coded so the next timeline is selected after that
> restart logic has run. This preserves the existing lock-drop traversal
> semantics and prepares the code for the list iterator update.

...

>  	spin_lock(&timelines->lock);
> -	list_for_each_entry(tl, &timelines->active_list, link) {
> +	for (tl = list_first_entry(&timelines->active_list, typeof(*tl), link);
> +	     !list_entry_is_head(tl, &timelines->active_list, link);
> +	     tl = list_next_entry(tl, link)) {

Yeah, these cases should rather be converted to do {} while or while-loop.
This will make the intention clearer and reduces the possibility that someone
mistakenly changes these back to use list_for_each_entry().

See, for example, deferred_probe_work_func() implementation.

-- 
With Best Regards,
Andy Shevchenko