Re: [PATCH v2] can: tcan4x5x: Turn on the power before parsing the config

From: Marc Kleine-Budde
Date: Thu Jan 02 2020 - 06:12:07 EST


On 12/10/19 5:32 PM, Dan Murphy wrote:
> The parse config function now performs action on the device either
> reading or writing and a reset. If the regulator is managed it needs
> to be turned on. So turn on the regulator if available if the parsing
> fails then turn off the regulator.
>
> Fixes: a5235f3c7c23 ("can: tcan45x: Make wake-up GPIO an optional GPIO")
> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> ---
>
> v2 - Added error handling and moved regulator_get to probe
>
> drivers/net/can/m_can/tcan4x5x.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
> index 4e1789ea2bc3..ddf7db498241 100644
> --- a/drivers/net/can/m_can/tcan4x5x.c
> +++ b/drivers/net/can/m_can/tcan4x5x.c
> @@ -374,11 +374,6 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
> if (IS_ERR(tcan4x5x->device_state_gpio))
> tcan4x5x->device_state_gpio = NULL;
>
> - tcan4x5x->power = devm_regulator_get_optional(cdev->dev,
> - "vsup");
> - if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
> - return -EPROBE_DEFER;
> -
> return 0;
> }
>
> @@ -412,6 +407,12 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
> if (!priv)
> return -ENOMEM;
>
> + priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
> + if (PTR_ERR(priv->power) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> + else
> + priv->power = NULL;
> +

BTW: you are leaking the netdev allocated with m_can_class_allocate_dev().

In order to fix this:

- introduce a m_can_class_free_dev() function that calls the
free_candev().
- fix error path in tcan4x5x_can_probe() and m_can_plat_probe() by
adding the missing m_can_class_free_dev()
- remove the free_candev() from the error path in m_can_class_register()
it makes no sense that this function free a ressource it has not
allocated
- remove the free_candev() from m_can_class_unregister()
it makes no sense that this function free a ressource it has not
allocated
- add needed m_can_class_free_dev() to tcan4x5x_can_remove() and
m_can_plat_remove()

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

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