linux-kernel - Re: [PATCH v5 07/12] drm/panfrost: Don't rework job IRQ enable mask in the enable path

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Message-ID: <dba3561f-f130-4f00-8206-c9cc16fce319@arm.com>
Date: Thu, 9 Oct 2025 16:33:43 +0100
From: Steven Price <steven.price@....com>
To: Adrián Larumbe <adrian.larumbe@...labora.com>,
 linux-kernel@...r.kernel.org
Cc: dri-devel@...ts.freedesktop.org,
 Boris Brezillon <boris.brezillon@...labora.com>, kernel@...labora.com,
 Rob Herring <robh@...nel.org>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Subject: Re: [PATCH v5 07/12] drm/panfrost: Don't rework job IRQ enable mask
 in the enable path

On 07/10/2025 16:01, Adrián Larumbe wrote:
> Up until now, panfrost_job_enable_interrupts() would always recalculate the
> same job IRQ enablement mask, which is effectively a constant.
> 
> Replace it with a compile-time constant value, and also in another couple
> places where an equivalent expression was being used.
> 
> Reviewed-by: Boris Brezillon <boris.brezillon@...labora.com>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@...labora.com>

Reviewed-by: Steven Price <steven.price@....com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_device.h |  4 ++++
>  drivers/gpu/drm/panfrost/panfrost_job.c    | 19 ++++---------------
>  2 files changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 474b232bb38e..ac7147ed806b 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -26,6 +26,10 @@ struct panfrost_perfcnt;
>  
>  #define MAX_PM_DOMAINS 5
>  
> +#define ALL_JS_INT_MASK					\
> +	(GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |		\
> +	 GENMASK(NUM_JOB_SLOTS - 1, 0))
> +
>  enum panfrost_drv_comp_bits {
>  	PANFROST_COMP_BIT_GPU,
>  	PANFROST_COMP_BIT_JOB,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index 1b3af5d52081..ff525d3efd76 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -428,17 +428,10 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
>  
>  void panfrost_job_enable_interrupts(struct panfrost_device *pfdev)
>  {
> -	int j;
> -	u32 irq_mask = 0;
> -
>  	clear_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended);
>  
> -	for (j = 0; j < NUM_JOB_SLOTS; j++) {
> -		irq_mask |= MK_JS_MASK(j);
> -	}
> -
> -	job_write(pfdev, JOB_INT_CLEAR, irq_mask);
> -	job_write(pfdev, JOB_INT_MASK, irq_mask);
> +	job_write(pfdev, JOB_INT_CLEAR, ALL_JS_INT_MASK);
> +	job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  }
>  
>  void panfrost_job_suspend_irq(struct panfrost_device *pfdev)
> @@ -757,9 +750,7 @@ panfrost_reset(struct panfrost_device *pfdev,
>  		drm_sched_start(&pfdev->js->queue[i].sched, 0);
>  
>  	/* Re-enable job interrupts now that everything has been restarted. */
> -	job_write(pfdev, JOB_INT_MASK,
> -		  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
> -		  GENMASK(NUM_JOB_SLOTS - 1, 0));
> +	job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  
>  	dma_fence_end_signalling(cookie);
>  }
> @@ -832,9 +823,7 @@ static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data)
>  
>  	/* Enable interrupts only if we're not about to get suspended */
>  	if (!test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended))
> -		job_write(pfdev, JOB_INT_MASK,
> -			  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
> -			  GENMASK(NUM_JOB_SLOTS - 1, 0));
> +		job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  
>  	return IRQ_HANDLED;
>  }