Re: [PATCH v2] media: imx7-mipi-csis: Add a check for devm_regulator_get

From: Rui Miguel Silva <rmfrfs@gmail.com>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: devel@driverdev.osuosl.org,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Chuhong Yuan <hslester96@gmail.com>,
	linux-kernel@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Steve Longerbeam <slongerbeam@gmail.com>,
	Shawn Guo <shawnguo@kernel.org>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Fabio Estevam <festevam@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-media@vger.kernel.org
Subject: Re: [PATCH v2] media: imx7-mipi-csis: Add a check for devm_regulator_get
Date: Wed, 16 Oct 2019 14:43:59 +0100	[thread overview]
Message-ID: <m336fsst40.fsf@gmail.com> (raw)
In-Reply-To: <20191016090628.7l5u4ytdqr2jlasg@pengutronix.de>

Hi Marco,
On Wed 16 Oct 2019 at 10:06, Marco Felsch wrote:
> Hi Chuhong,
>
> On 19-10-15 21:59, Chuhong Yuan wrote:
>> devm_regulator_get may return an error but mipi_csis_phy_init misses
>> a check for it.
>> This may lead to problems when regulator_set_voltage uses the unchecked
>> pointer.
>> This patch adds a check for devm_regulator_get to avoid potential risk.
>>
>> Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
>> ---
>> Changes in v2:
>>   - Add a check in mipi_csis_probe for the modified mipi_csis_phy_init.
>
> Did you miss the check for -EPROBE_DEFER?
>

I think nothing special is really needed to do in case of
EPROBE_DEFER, or am I missing something?
It just return to probe and probe returns also. I just talked
about it because it was not cover in the original code.

---
Cheers,
	Rui

>
> Regards,
>   Marco
>
>>
>>  drivers/staging/media/imx/imx7-mipi-csis.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
>> index 73d8354e618c..e8a6acaa969e 100644
>> --- a/drivers/staging/media/imx/imx7-mipi-csis.c
>> +++ b/drivers/staging/media/imx/imx7-mipi-csis.c
>> @@ -350,6 +350,8 @@ static void mipi_csis_sw_reset(struct csi_state *state)
>>  static int mipi_csis_phy_init(struct csi_state *state)
>>  {
>>  	state->mipi_phy_regulator = devm_regulator_get(state->dev, "phy");
>> +	if (IS_ERR(state->mipi_phy_regulator))
>> +		return PTR_ERR(state->mipi_phy_regulator);
>>
>>  	return regulator_set_voltage(state->mipi_phy_regulator, 1000000,
>>  				     1000000);
>> @@ -966,7 +968,10 @@ static int mipi_csis_probe(struct platform_device *pdev)
>>  		return ret;
>>  	}
>>
>> -	mipi_csis_phy_init(state);
>> +	ret = mipi_csis_phy_init(state);
>> +	if (ret < 0)
>> +		return ret;
>> +
>>  	mipi_csis_phy_reset(state);
>>
>>  	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> --
>> 2.20.1
>>
>>
>>

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