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

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

[Dan Murphy]

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@ti.com>
---

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;
+
 	mcan_class->device_data = priv;
 
 	m_can_class_get_clocks(mcan_class);
@@ -451,11 +452,13 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
 					&spi->dev, &tcan4x5x_regmap);
 
-	ret = tcan4x5x_parse_config(mcan_class);
+	ret = tcan4x5x_power_enable(priv->power, 1);
 	if (ret)
 		goto out_clk;
 
-	tcan4x5x_power_enable(priv->power, 1);
+	ret = tcan4x5x_parse_config(mcan_class);
+	if (ret)
+		goto out_power;
 
 	ret = m_can_class_register(mcan_class);
 	if (ret)
-- 
2.23.0

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

[Marc Kleine-Budde]

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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@ti.com>

Applied to linux-can.

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

[Marc Kleine-Budde]

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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@ti.com>
> ---
> 
> 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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Re: [PATCH v2] can: tcan4x5x: Turn on the power before parsing the config

[Marc Kleine-Budde]

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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.

Another BTW:
Consider converting the switching of the vsup to runtime_pm.

Yet another one:
Why do you disable the clocks in the error path of tcan4x5x_can_probe(),
but never enable them?

> out_clk:
> 	if (!IS_ERR(mcan_class->cclk)) {
> 		clk_disable_unprepare(mcan_class->cclk);
> 		clk_disable_unprepare(mcan_class->hclk);
> 	}

- please move the clock handling from the m_can.c to the individual
  driver
- please move the clock handling to runtime_pm in the individual driver
- remove the obsolete m_can_class_get_clocks()
- make runtime_pm mandatory

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

[Dan Murphy]

Marc

On 1/2/20 6:38 AM, Marc Kleine-Budde wrote:
> 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.
> Another BTW:
> Consider converting the switching of the vsup to runtime_pm.
>
> Yet another one:
> Why do you disable the clocks in the error path of tcan4x5x_can_probe(),
> but never enable them?
>
>> out_clk:
>> 	if (!IS_ERR(mcan_class->cclk)) {
>> 		clk_disable_unprepare(mcan_class->cclk);
>> 		clk_disable_unprepare(mcan_class->hclk);
>> 	}
> - please move the clock handling from the m_can.c to the individual
>    driver
> - please move the clock handling to runtime_pm in the individual driver
> - remove the obsolete m_can_class_get_clocks()
> - make runtime_pm mandatory

Ack to the above I have made these changes locally.  Will submit next week.

Dan


> regards,
> Marc
>

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

[Dan Murphy]

Marc

On 1/2/20 6:38 AM, Marc Kleine-Budde wrote:
> 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.
> Another BTW:
> Consider converting the switching of the vsup to runtime_pm.
>
> Yet another one:
> Why do you disable the clocks in the error path of tcan4x5x_can_probe(),
> but never enable them?
>
>> out_clk:
>> 	if (!IS_ERR(mcan_class->cclk)) {
>> 		clk_disable_unprepare(mcan_class->cclk);
>> 		clk_disable_unprepare(mcan_class->hclk);
>> 	}
> - please move the clock handling from the m_can.c to the individual
>    driver
> - please move the clock handling to runtime_pm in the individual driver
> - remove the obsolete m_can_class_get_clocks()
> - make runtime_pm mandatory
>
> regards,
> Marc
>
I have separate the clock calls into pm runtime calls and moved the 
clock init into the respective children of the framework.

Did you want me to submit 1 patch with all the changes or would you like 
3 separate patches?  First 2 patches will abstract the clocks away into 
the children and the 3rd patch would be to remove the clocks API from 
the framework

Dan

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

[Marc Kleine-Budde]

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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.

BTW n+1:
Why is the function called parse_config? I don't see any parsing going on.

Please add it directly to the tcan4x5x_can_probe() function.

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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