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: Thu, 17 Oct 2019 10:43:59 +0100	[thread overview]
Message-ID: <m31rvbso4g.fsf@gmail.com> (raw)
In-Reply-To: <20191017081029.q2czy7y5zlbj4ogr@pengutronix.de>

Hi Marco,
On Thu 17 Oct 2019 at 09:10, Marco Felsch wrote:
> Hi Rui,
>
> On 19-10-16 14:43, Rui Miguel Silva wrote:
>> 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.
>
> Yes, your are right... I shouldn't comment on anything I read with one
> eye. Sorry.
>

ehehe, no problem and thanks for your inputs.

---
Cheers,
	Rui

>
> Regards,
>   Marco
>
>> ---
>> 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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