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Message-ID: <03ba07c0-af10-4a99-7d5f-15d9a0cf853b@collabora.com>
Date:   Wed, 6 Jul 2022 10:23:29 +0200
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Subject: Re: [PATCH v2] PM: domains: Ensure genpd_debugfs_dir exists before
 remove
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To:     Hsin-Yi Wang <hsinyi@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     "Rafael J . Wysocki" <rafael@kernel.org>,
        Kevin Hilman <khilman@kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>,
        Pin-yen Lin <treapking@chromium.org>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220705171649.969194-1-hsinyi@chromium.org>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20220705171649.969194-1-hsinyi@chromium.org>
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Il 05/07/22 19:16, Hsin-Yi Wang ha scritto:
> Both genpd_debug_add() and genpd_debug_remove() may be called
> indirectly by other drivers while genpd_debugfs_dir is not yet
> set. For example, drivers can call pm_genpd_init() in probe or
> pm_genpd_init() in probe fail/cleanup path:
> 
> pm_genpd_init()
>   --> genpd_debug_add()
> 
> pm_genpd_remove()
>   --> genpd_remove()
>     --> genpd_debug_remove()
> 
> At this time, genpd_debug_init() may not yet be called.
> 
> genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it
> will return directly. Make sure this is also checked
> in pm_genpd_remove(), otherwise components under debugfs root
> which has the same name as other components under pm_genpd may
> be accidentally removed, since NULL represents debugfs root.
> 
> Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>