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

From: Marco Felsch <m.felsch@pengutronix.de>
To: Rui Miguel Silva <rmfrfs@gmail.com>
Cc: Chuhong Yuan <hslester96@gmail.com>,
	devel@driverdev.osuosl.org, Fabio Estevam <festevam@gmail.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	linux-kernel@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Steve Longerbeam <slongerbeam@gmail.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	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 10:10:29 +0200	[thread overview]
Message-ID: <20191017081029.q2czy7y5zlbj4ogr@pengutronix.de> (raw)
In-Reply-To: <m336fsst40.fsf@gmail.com>

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.

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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