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References: <20200614065251.94106-1-navid.emamdoost@gmail.com>
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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Sun, 14 Jun 2020 15:32:39 +0300
Message-ID: <CAHp75VfGHab7Oy5hhW+6rWxkcB5ZHif2hK7inbbdvfF-k0wX0A@mail.gmail.com>
Subject: Re: [PATCH] drm/vc4: fix ref count leak in vc4_dsi_encoder_enable
To:     Navid Emamdoost <navid.emamdoost@gmail.com>
Cc:     Eric Anholt <eric@anholt.net>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Navid Emamdoost <emamd001@umn.edu>, wu000273@umn.edu,
        Kangjie Lu <kjlu@umn.edu>, Stephen McCamant <smccaman@umn.edu>
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On Sun, Jun 14, 2020 at 9:55 AM Navid Emamdoost
<navid.emamdoost@gmail.com> wrote:
>
> in vc4_dsi_encoder_enable, the call to pm_runtime_get_sync increments
> the counter even in case of failure, leading to incorrect
> ref count. In case of failure, decrement the ref count before returning.

...

> +out:
> +       pm_runtime_put(dev);

Better to use pm_runtime_put_noidle() for error case.
And here is a change of semantics, i.e. before your patch there was no
put at all. How did you test this?

-- 
With Best Regards,
Andy Shevchenko