linux-kernel - Re: [PATCH] iommu/rockchip: Don't loop until failure to count interrupts

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Date:   Tue, 08 Oct 2019 19:58:14 +0200
From:   Heiko Stübner <heiko@...ech.de>
To:     Enric Balletbo i Serra <enric.balletbo@...labora.com>
Cc:     linux-kernel@...r.kernel.org, dianders@...omium.org,
        mka@...omium.org, groeck@...omium.org, kernel@...labora.com,
        bleung@...omium.org, linux-rockchip@...ts.infradead.org,
        iommu@...ts.linux-foundation.org, Joerg Roedel <joro@...tes.org>,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] iommu/rockchip: Don't loop until failure to count interrupts

Hi Enric,

Am Dienstag, 8. Oktober 2019, 15:58:43 CEST schrieb Enric Balletbo i Serra:
> As platform_get_irq() now prints an error when the interrupt does not
> exist, counting interrupts by looping until failure causes the printing
> of scary messages like:
> 
>  rk_iommu ff924000.iommu: IRQ index 1 not found
>  rk_iommu ff914000.iommu: IRQ index 1 not found
>  rk_iommu ff903f00.iommu: IRQ index 1 not found
>  rk_iommu ff8f3f00.iommu: IRQ index 1 not found
>  rk_iommu ff650800.iommu: IRQ index 1 not found
> 
> Fix this by using the platform_irq_count() helper to avoid touching
> non-existent interrupts.

It looks like we did the same fix ... see my patch from september 25:
https://patchwork.kernel.org/patch/11161221/


> Fixes: 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to platform_get_irq*()")
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@...labora.com>
> ---
> 
>  drivers/iommu/rockchip-iommu.c | 35 +++++++++++++++++++++++-----------
>  1 file changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
> index 26290f310f90..8c6318bd1b37 100644
> --- a/drivers/iommu/rockchip-iommu.c
> +++ b/drivers/iommu/rockchip-iommu.c
> @@ -1136,7 +1136,7 @@ static int rk_iommu_probe(struct platform_device *pdev)
>  	struct rk_iommu *iommu;
>  	struct resource *res;
>  	int num_res = pdev->num_resources;
> -	int err, i, irq;
> +	int err, i, irq, num_irqs;
>  
>  	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
>  	if (!iommu)
> @@ -1219,20 +1219,28 @@ static int rk_iommu_probe(struct platform_device *pdev)
>  
>  	pm_runtime_enable(dev);
>  
> -	i = 0;
> -	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO) {
> -		if (irq < 0)
> -			return irq;
> +	num_irqs = platform_irq_count(pdev);
> +	if (num_irqs < 0) {
> +		err = num_irqs;
> +		goto err_disable_pm_runtime;
> +	}

By moving the basic irq count above the pm_runtime_enable
you save some lines and the whole goto logic ... see my patch
for reference :-D

Heiko

> +
> +	for (i = 0; i < num_irqs; i++) {
> +		irq = platform_get_irq(pdev, i);
> +		if (irq < 0) {
> +			err = irq;
> +			goto err_disable_pm_runtime;
> +		}
>  
>  		err = devm_request_irq(iommu->dev, irq, rk_iommu_irq,
>  				       IRQF_SHARED, dev_name(dev), iommu);
> -		if (err) {
> -			pm_runtime_disable(dev);
> -			goto err_remove_sysfs;
> -		}
> +		if (err)
> +			goto err_disable_pm_runtime;
>  	}
>  
>  	return 0;
> +err_disable_pm_runtime:
> +	pm_runtime_disable(dev);
>  err_remove_sysfs:
>  	iommu_device_sysfs_remove(&iommu->iommu);
>  err_put_group:
> @@ -1245,10 +1253,15 @@ static int rk_iommu_probe(struct platform_device *pdev)
>  static void rk_iommu_shutdown(struct platform_device *pdev)
>  {
>  	struct rk_iommu *iommu = platform_get_drvdata(pdev);
> -	int i = 0, irq;
> +	int i, irq, num_irqs;
>  
> -	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO)
> +	num_irqs = platform_irq_count(pdev);
> +	for (i = 0; i < num_irqs; i++) {
> +		irq = platform_get_irq(pdev, i);
> +		if (irq < 0)
> +			continue;
>  		devm_free_irq(iommu->dev, irq, iommu);
> +	}
>  
>  	pm_runtime_force_suspend(&pdev->dev);
>  }
>