Re: [PATCH v1 2/3] drm/msm/dpu: hw_intr: always call dpu_hw_intr_clear_intr_status_nolock

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Sun 11 Apr 19:09 CDT 2021, Dmitry Baryshkov wrote:

> Always call dpu_hw_intr_clear_intr_status_nolock() from the
> dpu_hw_intr_dispatch_irqs(). This simplifies the callback function
> (which call clears the interrupts anyway) and enforces clearing the hw
> interrupt status.
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c  |  9 -----
>  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 39 +++++++++----------
>  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h |  9 -----
>  3 files changed, 18 insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
> index 54b34746a587..fd11a2aeab6c 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
> @@ -41,15 +41,6 @@ static void dpu_core_irq_callback_handler(void *arg, int irq_idx)
>  		if (cb->func)
>  			cb->func(cb->arg, irq_idx);
>  	spin_unlock_irqrestore(&dpu_kms->irq_obj.cb_lock, irq_flags);
> -
> -	/*
> -	 * Clear pending interrupt status in HW.
> -	 * NOTE: dpu_core_irq_callback_handler is protected by top-level
> -	 *       spinlock, so it is safe to clear any interrupt status here.
> -	 */
> -	dpu_kms->hw_intr->ops.clear_intr_status_nolock(
> -			dpu_kms->hw_intr,
> -			irq_idx);
>  }
>  
>  int dpu_core_irq_idx_lookup(struct dpu_kms *dpu_kms,
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> index cf9bfd45aa59..8bd22e060437 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> @@ -1362,6 +1362,22 @@ static int dpu_hw_intr_irqidx_lookup(struct dpu_hw_intr *intr,
>  	return -EINVAL;
>  }
>  
> +static void dpu_hw_intr_clear_intr_status_nolock(struct dpu_hw_intr *intr,
> +		int irq_idx)
> +{
> +	int reg_idx;
> +
> +	if (!intr)
> +		return;
> +
> +	reg_idx = dpu_irq_map[irq_idx].reg_idx;
> +	DPU_REG_WRITE(&intr->hw, dpu_intr_set[reg_idx].clr_off,
> +			dpu_irq_map[irq_idx].irq_mask);
> +
> +	/* ensure register writes go through */
> +	wmb();
> +}
> +
>  static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
>  		void (*cbfunc)(void *, int),
>  		void *arg)
> @@ -1430,9 +1446,8 @@ static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
>  				 */
>  				if (cbfunc)
>  					cbfunc(arg, irq_idx);
> -				else
> -					intr->ops.clear_intr_status_nolock(
> -							intr, irq_idx);
> +
> +				dpu_hw_intr_clear_intr_status_nolock(intr, irq_idx);
>  
>  				/*
>  				 * When callback finish, clear the irq_status
> @@ -1597,23 +1612,6 @@ static int dpu_hw_intr_disable_irqs(struct dpu_hw_intr *intr)
>  	return 0;
>  }
>  
> -
> -static void dpu_hw_intr_clear_intr_status_nolock(struct dpu_hw_intr *intr,
> -		int irq_idx)
> -{
> -	int reg_idx;
> -
> -	if (!intr)
> -		return;
> -
> -	reg_idx = dpu_irq_map[irq_idx].reg_idx;
> -	DPU_REG_WRITE(&intr->hw, dpu_intr_set[reg_idx].clr_off,
> -			dpu_irq_map[irq_idx].irq_mask);
> -
> -	/* ensure register writes go through */
> -	wmb();
> -}
> -
>  static u32 dpu_hw_intr_get_interrupt_status(struct dpu_hw_intr *intr,
>  		int irq_idx, bool clear)
>  {
> @@ -1655,7 +1653,6 @@ static void __setup_intr_ops(struct dpu_hw_intr_ops *ops)
>  	ops->dispatch_irqs = dpu_hw_intr_dispatch_irq;
>  	ops->clear_all_irqs = dpu_hw_intr_clear_irqs;
>  	ops->disable_all_irqs = dpu_hw_intr_disable_irqs;
> -	ops->clear_intr_status_nolock = dpu_hw_intr_clear_intr_status_nolock;
>  	ops->get_interrupt_status = dpu_hw_intr_get_interrupt_status;
>  }
>  
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> index 5a1c304ba93f..5bade5637ecc 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> @@ -142,15 +142,6 @@ struct dpu_hw_intr_ops {
>  			void (*cbfunc)(void *arg, int irq_idx),
>  			void *arg);
>  
> -	/**
> -	 * clear_intr_status_nolock() - clears the HW interrupts without lock
> -	 * @intr:	HW interrupt handle
> -	 * @irq_idx:	Lookup irq index return from irq_idx_lookup
> -	 */
> -	void (*clear_intr_status_nolock)(
> -			struct dpu_hw_intr *intr,
> -			int irq_idx);
> -
>  	/**
>  	 * get_interrupt_status - Gets HW interrupt status, and clear if set,
>  	 *                        based on given lookup IRQ index.
> -- 
> 2.30.2
>