Re: [PATCH 2/2] driver core: platform: provide devm_platform_iounremap_resource

From: pierre kuo <vichy.kuo@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: rafael@kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] driver core: platform: provide devm_platform_iounremap_resource
Date: Mon, 5 Oct 2020 23:23:18 +0800	[thread overview]
Message-ID: <CAOVJa8G+RMYvV6hU1cuJStRBM=7BbA7s1sXZavKs9OhHY8kaZw@mail.gmail.com> (raw)
In-Reply-To: <20201004164745.GA196660@kroah.com>

hi Greg:
> Why are you adding new functions but not actually calling them anywhere?

Below patch introduce a single helper, devm_platform_ioremap_resource,
which combines
platform_get_resource() and devm_ioremap_resource(). But there is no
single helper to release
those resources in driver removing stage.

https://lore.kernel.org/lkml/20190215152507.31066-2-brgl@bgdev.pl/

That means driver owner still need to call below (*) and (**) for
releasing resource.
Therefore, this patch adds a single release helper that can be paired with
devm_platform_ioremap_resource.

Appreciate ur kind help,

foo_probe(pdev)
{
    iomem = devm_platform_ioremap_resource(pdev, 0);
    ....
}

foo_remove(pdev)
{
    devm_iounmap(iomem);   (*)
    devm_release_mem_region(dev, res->start, size); (**)
   ........................
}