[PATCH 16/21] perf/cxlpmu: Replace IRQF_ONESHOT with IRQF_NO_THREAD

[PATCH 16/21] perf/cxlpmu: Replace IRQF_ONESHOT with IRQF_NO_THREAD

[Sebastian Andrzej Siewior]

Passing IRQF_ONESHOT ensures that the interrupt source is masked until
the secondary (threaded) handler is done. If only a primary handler is
used then the flag makes no sense because the interrupt can not fire
(again) while its handler is running.
The flag also disallows force-threading of the primary handler and the
irq-core will warn about this.

The intention here was probably not allowing forced-threading.

Replace IRQF_ONESHOT with IRQF_NO_THREAD.

Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-cxl@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/perf/cxl_pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c
index d094030220bf2..68a54d97d2a8a 100644
--- a/drivers/perf/cxl_pmu.c
+++ b/drivers/perf/cxl_pmu.c
@@ -877,7 +877,7 @@ static int cxl_pmu_probe(struct device *dev)
 	if (!irq_name)
 		return -ENOMEM;
 
-	rc = devm_request_irq(dev, irq, cxl_pmu_irq, IRQF_SHARED | IRQF_ONESHOT,
+	rc = devm_request_irq(dev, irq, cxl_pmu_irq, IRQF_SHARED | IRQF_NO_THREAD,
 			      irq_name, info);
 	if (rc)
 		return rc;
-- 
2.51.0

Re: [PATCH 16/21] perf/cxlpmu: Replace IRQF_ONESHOT with IRQF_NO_THREAD

[Jonathan Cameron]

On Fri, 23 Jan 2026 12:37:02 +0100
Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:

> Passing IRQF_ONESHOT ensures that the interrupt source is masked until
> the secondary (threaded) handler is done. If only a primary handler is
> used then the flag makes no sense because the interrupt can not fire
> (again) while its handler is running.
> The flag also disallows force-threading of the primary handler and the
> irq-core will warn about this.
> 
> The intention here was probably not allowing forced-threading.
> 
> Replace IRQF_ONESHOT with IRQF_NO_THREAD.
> 
I don't think we are that likely to see force-threading on CXL
systems (I could be wrong!), but still good to correct this.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-cxl@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  drivers/perf/cxl_pmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c
> index d094030220bf2..68a54d97d2a8a 100644
> --- a/drivers/perf/cxl_pmu.c
> +++ b/drivers/perf/cxl_pmu.c
> @@ -877,7 +877,7 @@ static int cxl_pmu_probe(struct device *dev)
>  	if (!irq_name)
>  		return -ENOMEM;
>  
> -	rc = devm_request_irq(dev, irq, cxl_pmu_irq, IRQF_SHARED | IRQF_ONESHOT,
> +	rc = devm_request_irq(dev, irq, cxl_pmu_irq, IRQF_SHARED | IRQF_NO_THREAD,
>  			      irq_name, info);
>  	if (rc)
>  		return rc;