Re: [PATCH 06/10] drm/panthor: Prepare the scheduler logic for FW events in IRQ context

[Boris Brezillon <boris.brezillon@collabora.com>]

On Fri, 1 May 2026 14:47:59 +0100
Steven Price <steven.price@arm.com> wrote:

> On 29/04/2026 10:38, Boris Brezillon wrote:
> > Add a specific spinlock for events processing, and force processing
> > of events in the panthor_sched_report_fw_events() path rather than
> > deferring it to a work item. We also fast-track fence signalling by
> > making the job completion logic IRQ-safe.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>  
> 
> I think there's some locking problems here. With some AI help I found
> the following path:
> 
>  * panthor_job_irq_handler()
>   * panthor_sched_report_fw_events()
>    * [takes events_lock]
>    * sched_process_csg_irq_locked()
>     * csg_slot_process_progress_timer_event_locked()
>      * lockdep_assert_held(&sched->lock);

Oops, this one should check that events_lock is held instead. I'll fix
that.