linux-kernel - Re: [PATCH v3] coccinelle: api: semantic patch to use pm_runtime_resume_and

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Date:   Tue, 27 Apr 2021 17:05:28 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Julia Lawall <Julia.Lawall@...ia.fr>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>,
        Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        kernel-janitors@...r.kernel.org,
        Gilles Muller <Gilles.Muller@...ia.fr>,
        Nicolas Palix <nicolas.palix@...g.fr>,
        Michal Marek <michal.lkml@...kovi.net>, cocci@...teme.lip6.fr,
        linux-kernel@...r.kernel.org,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Zhang Qilong <zhangqilong3@...wei.com>,
        Jakub Kicinski <kuba@...nel.org>
Subject: Re: [PATCH v3] coccinelle: api: semantic patch to use
 pm_runtime_resume_and_get

On Tue, Apr 27, 2021 at 02:58:34PM +0200, Julia Lawall wrote:
> pm_runtime_get_sync keeps a reference count on failure, which can lead
> to leaks.  pm_runtime_resume_and_get drops the reference count in the
> failure case.  This rule very conservatively follows the definition of
> pm_runtime_resume_and_get to address the cases where the reference
> count is unlikely to be needed in the failure case.  Specifically, the
> change is only done when pm_runtime_get_sync is followed immediately
> by an if and when the branch of the if is immediately a call to
> pm_runtime_put_noidle (like in the definition of
> pm_runtime_resume_and_get) or something that is likely a print
> statement followed by a pm_runtime_resume_and_get call.  The patch

s/pm_runtime_resume_and_get/pm_runtime_put_noidle/

> case appears somewhat more complicated, because it also deals with the
> cases where {}s need to be removed.
> 
> pm_runtime_resume_and_get was introduced in
> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to
> deal with usage counter")
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@...ia.fr>
> 
> ---
> v3: add the people who signed off on commit dd8088d5a896, expand the log message
> v2: better keyword

Johan