2019-10-14 02:13:17

by Chuhong Yuan

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

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 <[email protected]>
---
drivers/staging/media/imx/imx7-mipi-csis.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
index 73d8354e618c..9a07b54c4ab1 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);
--
2.20.1

2019-10-15 11:13:49

by Rui Miguel Silva

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

Hi Chuhong,
Thanks for the patch.

On Mon 14 Oct 2019 at 03:08, 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 <[email protected]>
> ---
> drivers/staging/media/imx/imx7-mipi-csis.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
> index 73d8354e618c..9a07b54c4ab1 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);

This regulator is marked as mandatory in the device tree entry,
however it looks good to me to have this check, even because it
can return -EPROBE_DEFER and we need to retry.

But for that we may need to extend this patch to make the caller
of this (mipi_csis_probe), to also really care about the returned
code.

Cheers,
Rui

>
> return regulator_set_voltage(state->mipi_phy_regulator, 1000000,
> 1000000);