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Date:   Wed, 8 Jul 2020 14:25:42 +0200
From:   Maxime Ripard <maxime@cerno.tech>
To:     Ondrej Jirman <megous@megous.com>
Cc:     linux-sunxi@googlegroups.com,
        Vasily Khoruzhick <anarsoul@gmail.com>,
        Yangtao Li <tiny.windzz@gmail.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amit.kucheria@verdurent.com>,
        Chen-Yu Tsai <wens@csie.org>,
        "open list:ALLWINNER THERMAL DRIVER" <linux-pm@vger.kernel.org>,
        "moderated list:ARM/Allwinner sunXi SoC support" 
        <linux-arm-kernel@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] thermal: sun8i: Be loud when probe fails
Message-ID: <20200708122542.73o3lbhgvbdw5c4z@gilmour.lan>
References: <20200708105527.868987-1-megous@megous.com>
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Hi,

On Wed, Jul 08, 2020 at 12:55:27PM +0200, Ondrej Jirman wrote:
> I noticed several mobile Linux distributions failing to enable the
> thermal regulation correctly, because the kernel is silent
> when thermal driver fails to probe. Add enough error reporting
> to debug issues and warn users in case thermal sensor is failing
> to probe.
>=20
> Failing to notify users means, that SoC can easily overheat under
> load.
>=20
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> ---
>  drivers/thermal/sun8i_thermal.c | 55 ++++++++++++++++++++++++++-------
>  1 file changed, 43 insertions(+), 12 deletions(-)
>=20
> diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_ther=
mal.c
> index 74d73be16496..9065e79ae743 100644
> --- a/drivers/thermal/sun8i_thermal.c
> +++ b/drivers/thermal/sun8i_thermal.c
> @@ -287,8 +287,12 @@ static int sun8i_ths_calibrate(struct ths_device *tm=
dev)
> =20
>  	calcell =3D devm_nvmem_cell_get(dev, "calibration");
>  	if (IS_ERR(calcell)) {
> +		dev_err(dev, "Failed to get calibration nvmem cell (%ld)\n",
> +			PTR_ERR(calcell));
> +
>  		if (PTR_ERR(calcell) =3D=3D -EPROBE_DEFER)
>  			return -EPROBE_DEFER;
> +

The rest of the patch makes sense, but we should probably put the error
message after the EPROBE_DEFER return so that we don't print any extra
noise that isn't necessarily useful

Maxime