On Tue, May 12, 2026 at 4:54 AM Boris Brezillon
<[email protected]> wrote:
>
> All drivers except panthor signal their fences from their interrupt
> handler to minimize latency. We could do the same from the threaded
> handler, but the latency is still quite high in that case, so let's
> allow components to choose the context they want their IRQ handler
> to run in by exposing support for custom hard handlers.
>
> Reviewed-by: Liviu Dudau <[email protected]>
> Reviewed-by: Steven Price <[email protected]>
> Signed-off-by: Boris Brezillon <[email protected]>
> ---
> drivers/gpu/drm/panthor/panthor_device.h | 11 ++++++++---
> drivers/gpu/drm/panthor/panthor_fw.c | 1 +
> drivers/gpu/drm/panthor/panthor_gpu.c | 1 +
> drivers/gpu/drm/panthor/panthor_mmu.c | 1 +
> drivers/gpu/drm/panthor/panthor_pwr.c | 1 +
> 5 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_device.h
> b/drivers/gpu/drm/panthor/panthor_device.h
> index 393fcda73d88..1aaf06df875b 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -672,6 +672,7 @@ static inline void panthor_irq_disable_events(struct
> panthor_irq *pirq, u32 mask
> static inline int
> panthor_irq_request(struct panthor_device *ptdev, struct panthor_irq *pirq,
> int irq, u32 mask, void __iomem *iomem, const char *name,
> + irqreturn_t (*raw_handler)(int, void *data),
> irqreturn_t (*threaded_handler)(int, void *data))
> {
> const char *full_name;
> @@ -687,9 +688,13 @@ panthor_irq_request(struct panthor_device *ptdev, struct
> panthor_irq *pirq,
> return -ENOMEM;
>
> panthor_irq_resume(pirq);
> - return devm_request_threaded_irq(ptdev->base.dev, irq,
> - panthor_irq_default_raw_handler,
> - threaded_handler,
> +
> + if (!threaded_handler) {
> + return devm_request_irq(ptdev->base.dev, irq, raw_handler,
> + IRQF_SHARED, full_name, pirq);
> + }
devm_request_irq expands to devm_request_threaded_irq plus
IRQF_COND_ONESHOT. This appears redundant.
> +
> + return devm_request_threaded_irq(ptdev->base.dev, irq, raw_handler,
> threaded_handler,
> IRQF_SHARED, full_name, pirq);
> }
>
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c
> b/drivers/gpu/drm/panthor/panthor_fw.c
> index eaf599b0a887..8239a6951569 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -1483,6 +1483,7 @@ int panthor_fw_init(struct panthor_device *ptdev)
>
> ret = panthor_irq_request(ptdev, &fw->irq, irq, 0,
> ptdev->iomem + JOB_INT_BASE, "job",
> + panthor_irq_default_raw_handler,
> panthor_job_irq_threaded_handler);
> if (ret) {
> drm_err(&ptdev->base, "failed to request job irq");
> diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c
> b/drivers/gpu/drm/panthor/panthor_gpu.c
> index ce208e384762..d0be758ea3e1 100644
> --- a/drivers/gpu/drm/panthor/panthor_gpu.c
> +++ b/drivers/gpu/drm/panthor/panthor_gpu.c
> @@ -177,6 +177,7 @@ int panthor_gpu_init(struct panthor_device *ptdev)
> ret = panthor_irq_request(ptdev, &ptdev->gpu->irq, irq,
> GPU_INTERRUPTS_MASK,
> ptdev->iomem + GPU_INT_BASE, "gpu",
> + panthor_irq_default_raw_handler,
> panthor_gpu_irq_threaded_handler);
> if (ret)
> return ret;
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 375022fb3fd8..2955b8baa2e2 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -3266,6 +3266,7 @@ int panthor_mmu_init(struct panthor_device *ptdev)
> ret = panthor_irq_request(ptdev, &mmu->irq, irq,
> panthor_mmu_fault_mask(ptdev, ~0),
> ptdev->iomem + MMU_INT_BASE, "mmu",
> + panthor_irq_default_raw_handler,
> panthor_mmu_irq_threaded_handler);
> if (ret)
> return ret;
> diff --git a/drivers/gpu/drm/panthor/panthor_pwr.c
> b/drivers/gpu/drm/panthor/panthor_pwr.c
> index 80cf78007896..1efb7f3482ba 100644
> --- a/drivers/gpu/drm/panthor/panthor_pwr.c
> +++ b/drivers/gpu/drm/panthor/panthor_pwr.c
> @@ -491,6 +491,7 @@ int panthor_pwr_init(struct panthor_device *ptdev)
> err = panthor_irq_request(
> ptdev, &pwr->irq, irq, PWR_INTERRUPTS_MASK,
> pwr->iomem + PWR_INT_BASE, "pwr",
> + panthor_irq_default_raw_handler,
> panthor_pwr_irq_threaded_handler);
> if (err)
> return err;
>
> --
> 2.54.0
>
