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References: <20230508043641.23807-1-yejunyan@hust.edu.cn>
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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Mon, 8 May 2023 08:12:46 +0200
Message-ID: <CACRpkdb=dB2y_AtmMWOt0FAyLBFrJNCSqZrWGn97ciVTwLnbBw@mail.gmail.com>
Subject: Re: [PATCH v3] pci: controller: pci-ftpci100: Release the clock resources
To:     Junyan Ye <yejunyan@hust.edu.cn>
Cc:     Lorenzo Pieralisi <lpieralisi@kernel.org>,
        =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Wei Yongjun <weiyongjun1@huawei.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>,
        hust-os-kernel-patches@googlegroups.com,
        Dongliang Mu <dzm91@hust.edu.cn>, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Mon, May 8, 2023 at 6:41=E2=80=AFAM Junyan Ye <yejunyan@hust.edu.cn> wro=
te:

> Smatch reported:
> 1. drivers/pci/controller/pci-ftpci100.c:526 faraday_pci_probe() warn:
> 'clk' from clk_prepare_enable() not released on lines: 442,451,462,478,51=
2,517.
> 2. drivers/pci/controller/pci-ftpci100.c:526 faraday_pci_probe() warn:
> 'p->bus_clk' from clk_prepare_enable() not released on lines: 451,462,478=
,512,517.
>
> The clock resource is obtained by devm_clk_get(), and then
> clk_prepare_enable() makes the clock resource ready for use. After that,
> clk_disable_unprepare() should be called to release the clock resource
> when it is no longer needed. However, while doing some error handling
> in faraday_pci_probe(), clk_disable_unprepare() is not called to release
> clk and p->bus_clk before returning. These return lines are exactly 442,
> 451, 462, 478, 512, 517.
>
> Fix this warning by replacing devm_clk_get() with devm_clk_get_enabled(),
> which is equivalent to devm_clk_get() + clk_prepare_enable(). And with
> devm_clk_get_enabled(), the clock will automatically be disabled,
> unprepared and freed when the device is unbound from the bus.
>
> Fixes: b3c433efb8a3 ("PCI: faraday: Fix wrong pointer passed to PTR_ERR()=
")
> Fixes: 2eeb02b28579 ("PCI: faraday: Add clock handling")
> Fixes: 783a862563f7 ("PCI: faraday: Use pci_parse_request_of_pci_ranges()=
")
> Fixes: d3c68e0a7e34 ("PCI: faraday: Add Faraday Technology FTPCI100 PCI H=
ost Bridge driver")
> Fixes: f1e8bd21e39e ("PCI: faraday: Convert IRQ masking to raw PCI config=
 accessors")
> Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
> Signed-off-by: Junyan Ye <yejunyan@hust.edu.cn>
> ---
> v2 -> v3: Rebase to v6.4-rc1 and modify commit message.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
It's a fine fix since it saves lots of code.

I would merge it as a non-urgent fix.

Yours,
Linus Walleij