[PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Daniel Mack]

The reset GPIO line is acquired in cs4271_probe(), so it should be
freed from cs4271_remove() as well. This way, the driver can unloaded
and reloaded more than once.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 sound/soc/codecs/cs4271.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/cs4271.c b/sound/soc/codecs/cs4271.c
index ce05fd9..aeaa5c6 100644
--- a/sound/soc/codecs/cs4271.c
+++ b/sound/soc/codecs/cs4271.c
@@ -604,9 +604,11 @@ static int cs4271_remove(struct snd_soc_codec *codec)
 {
 	struct cs4271_private *cs4271 = snd_soc_codec_get_drvdata(codec);
 
-	if (gpio_is_valid(cs4271->gpio_nreset))
+	if (gpio_is_valid(cs4271->gpio_nreset)) {
 		/* Set codec to the reset state */
 		gpio_set_value(cs4271->gpio_nreset, 0);
+		devm_gpio_free(codec->dev, cs4271->gpio_nreset);
+	}
 
 	return 0;
 };
-- 
1.8.5.3

Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Mark Brown]

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On Wed, Feb 19, 2014 at 12:07:12PM +0100, Daniel Mack wrote:

> +	if (gpio_is_valid(cs4271->gpio_nreset)) {
>  		/* Set codec to the reset state */
>  		gpio_set_value(cs4271->gpio_nreset, 0);
> +		devm_gpio_free(codec->dev, cs4271->gpio_nreset);
> +	}

If it's being requested as a managed resource shouldn't it be being
freed automatically?

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Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Daniel Mack]

On 02/19/2014 12:15 PM, Mark Brown wrote:
> On Wed, Feb 19, 2014 at 12:07:12PM +0100, Daniel Mack wrote:
> 
>> +	if (gpio_is_valid(cs4271->gpio_nreset)) {
>>  		/* Set codec to the reset state */
>>  		gpio_set_value(cs4271->gpio_nreset, 0);
>> +		devm_gpio_free(codec->dev, cs4271->gpio_nreset);
>> +	}
> 
> If it's being requested as a managed resource shouldn't it be being
> freed automatically?
> 

Nope, as the module itself will not go away necessarily. I hit the bug
when unloading and reloading the machine driver. cs4271_probe(codec)
will fail to acquire and drive the reset line, and the codec stays in reset.

Daniel

Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Mark Brown]

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On Wed, Feb 19, 2014 at 12:24:23PM +0100, Daniel Mack wrote:
> On 02/19/2014 12:15 PM, Mark Brown wrote:
> > On Wed, Feb 19, 2014 at 12:07:12PM +0100, Daniel Mack wrote:

> >> +	if (gpio_is_valid(cs4271->gpio_nreset)) {
> >>  		/* Set codec to the reset state */
> >>  		gpio_set_value(cs4271->gpio_nreset, 0);
> >> +		devm_gpio_free(codec->dev, cs4271->gpio_nreset);
> >> +	}

> > If it's being requested as a managed resource shouldn't it be being
> > freed automatically?

> Nope, as the module itself will not go away necessarily. I hit the bug
> when unloading and reloading the machine driver. cs4271_probe(codec)
> will fail to acquire and drive the reset line, and the codec stays in reset.

The fix here is to move the resource acquisition to the bus level probe
instead of the ASoC card startup.

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Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Daniel Mack]

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On 02/19/2014 12:43 PM, Mark Brown wrote:
> On Wed, Feb 19, 2014 at 12:24:23PM +0100, Daniel Mack wrote:
>> On 02/19/2014 12:15 PM, Mark Brown wrote:
>>> On Wed, Feb 19, 2014 at 12:07:12PM +0100, Daniel Mack wrote:
> 
>>>> +	if (gpio_is_valid(cs4271->gpio_nreset)) { /* Set codec to
>>>> the reset state */ gpio_set_value(cs4271->gpio_nreset, 0); +
>>>> devm_gpio_free(codec->dev, cs4271->gpio_nreset); +	}
> 
>>> If it's being requested as a managed resource shouldn't it be
>>> being freed automatically?
> 
>> Nope, as the module itself will not go away necessarily. I hit
>> the bug when unloading and reloading the machine driver.
>> cs4271_probe(codec) will fail to acquire and drive the reset
>> line, and the codec stays in reset.
> 
> The fix here is to move the resource acquisition to the bus level
> probe instead of the ASoC card startup.
> 

Alright. I thought there was a verdict once that resource claiming
should be done right before usage, but you're right, it really rather
belongs into the bus probe functions.

I'll send another version.


Thanks!
Daniel

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Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Mark Brown]

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On Wed, Feb 19, 2014 at 01:09:27PM +0100, Daniel Mack wrote:

> Alright. I thought there was a verdict once that resource claiming
> should be done right before usage, but you're right, it really rather
> belongs into the bus probe functions.

No, that's not ever been the case as far as I can recall.  There were
some things it used to not be possible to do due to the ASoC level I/O
only working after the card comes up but that's a different issue.

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Re: [PATCH] ASoC: cs4271: free reset gpio in cs4271_remove()

[Lars-Peter Clausen]

On 02/19/2014 12:24 PM, Daniel Mack wrote:
> On 02/19/2014 12:15 PM, Mark Brown wrote:
>> On Wed, Feb 19, 2014 at 12:07:12PM +0100, Daniel Mack wrote:
>>
>>> +	if (gpio_is_valid(cs4271->gpio_nreset)) {
>>>   		/* Set codec to the reset state */
>>>   		gpio_set_value(cs4271->gpio_nreset, 0);
>>> +		devm_gpio_free(codec->dev, cs4271->gpio_nreset);
>>> +	}
>>
>> If it's being requested as a managed resource shouldn't it be being
>> freed automatically?
>>
>
> Nope, as the module itself will not go away necessarily. I hit the bug
> when unloading and reloading the machine driver. cs4271_probe(codec)
> will fail to acquire and drive the reset line, and the codec stays in reset.
>

In my opinion a better solution is to move the requesting of the GPIO from 
the CODEC probe() function to the SPI/I2C probe() functions. Actually it 
looks as if most of the code (if not all) in the CODEC probe() function 
should be done when the driver is probed.

- Lars