Re: [PATCH v2] cxl/events: Return IRQ_NONE when no event is pending

[Alison Schofield <alison.schofield@intel.com>]

On Sat, Sep 12, 2026 at 03:08:15PM +0530, Shaikh Kamaluddin wrote:
> CXL event interrupts may share an MSI/MSI-X vector with other event
> logs or device features. Consequently, cxl_event_thread() is registered
> with IRQF_SHARED and must determine whether the event-log facility
> claimed the interrupt.
> 
> The handler masks the Device Event Status register to the event logs
> supported by the driver. However, when no supported status bit is set,
> it exits the processing loop and still returns IRQ_HANDLED. This
> incorrectly reports that the interrupt was claimed and prevents the
> generic spurious-interrupt detector from accounting it as unhandled.
> 
> Track whether the CXL event handler claimed the interrupt and return
> IRQ_NONE when no supported event is detected. If no handler sharing the
> vector claims a sustained interrupt storm, the generic spurious-
> interrupt detector can eventually identify and disable the affected
> IRQ.

Reviewed-by: Alison Schofield <alison.schofield@intel.com>