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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Mon, 22 Apr 2024 08:00:17 +0300
To: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>, Joerg Roedel <joro@8bytes.org>,
	linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
	devicetree@vger.kernel.org, Rob Herring <robh@kernel.org>,
	Saravana Kannan <saravanak@google.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Hanjun Guo <guohanjun@huawei.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>
Subject: Re: [PATCH 1/4] iommu: Resolve fwspec ops automatically
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References: <cover.1713523251.git.robin.murphy@arm.com>
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Fri, Apr 19, 2024 at 05:55:59PM +0100, Robin Murphy kirjoitti:
> There's no real need for callers to resolve ops from a fwnode in order
> to then pass both to iommu_fwspec_init() - it's simpler and more sensible
> for that to resolve the ops itself. This in turn means we can centralise
> the notion of checking for a present driver, and enforce that fwspecs
> aren't allocated unless and until we know they will be usable.
> 
> Also we've grown a generic fwnode_handle_get() since this code was first
> written, so may as well clear up that ugly mismatch while we're in here.

..

> +++ b/drivers/iommu/mtk_iommu_v1.c

>  	if (!fwspec) {
> -		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
> +		ret = iommu_fwspec_init(dev, &args->np->fwnode);

I'm wondering, while at it, if can avoid direct dereference of fwnode by using of_fwnode_handle().

>  		if (ret)
>  			return ret;

..

> +++ b/drivers/iommu/of_iommu.c

> -	ret = iommu_fwspec_init(dev, fwnode, ops);
> +	ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode);

Ditto.

> +	if (ret == -EPROBE_DEFER)
> +		return driver_deferred_probe_check_state(dev);
>  	if (ret)
>  		return ret;

..

> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c

> -	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
> +	err = iommu_fwspec_init(dev, &dev->of_node->fwnode);

Ditto.

>  	if (err < 0) {
>  		dev_err(dev, "failed to initialize fwspec: %d\n", err);
>  		return err;

-- 
With Best Regards,
Andy Shevchenko