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From:   "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Date:   Thu, 27 Oct 2022 13:01:52 +0100
Message-ID: <CA+V-a8szaPjwumrBgOT9gzMKBjY7hk0zfP8RgzUUDfY+BAsogA@mail.gmail.com>
Subject: Re: [PATCH v2 2/5] media: i2c: ov5645: Use runtime PM
To:     Sakari Ailus <sakari.ailus@linux.intel.com>
Cc:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Shawn Tu <shawnx.tu@intel.com>,
        Jacopo Mondi <jacopo@jmondi.org>, linux-media@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org,
        Biju Das <biju.das.jz@bp.renesas.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
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Hi Sakari,

On Thu, Oct 27, 2022 at 12:20 PM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Prabhakar,
>
> One more comment.
>
> On Fri, Oct 14, 2022 at 07:34:56PM +0100, Prabhakar wrote:
> > @@ -1209,12 +1190,16 @@ static int ov5645_probe(struct i2c_client *client)
> >
> >       dev_info(dev, "OV5645 detected at address 0x%02x\n", client->addr);
> >
> > +     pm_runtime_set_active(dev);
> > +     pm_runtime_get_noresume(dev);
> > +     pm_runtime_enable(dev);
>
> You won't gain anything by eanbling runtime PM here. Just move it to the
> end of the function before the rest of the calls. Error handling becomes
> more simple.
>
If I move the above calls below I get the below warning:

[    2.633386] ov5645 0-003c: Runtime PM usage count underflow!

This is because of the last patch which moves ov5645_entity_init_cfg()
before registering the subdev. ov5645_entity_init_cfg() calls s_ctrl
due to which we are seeing the above message. Please let me know how
to proceed on this.

Cheers,
Prabhakar