[PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[Charles Keepax]

As the HPDET can't be aborted mid way through we should not allow any new
insertion to be processed until the previous HPDET has finished. It is very
unlikely but with low enough debounce settings you could start a new HPDET
before the old one has completed, which results in an erroneous reading.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---

Changes since v1:
 - Added defines for the count and delay
 - Added a comment to explain why we call arizona_hpdet_wait

Thanks,
Charles

 drivers/extcon/extcon-arizona.c | 45 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
index ed78b7c..df98d84 100644
--- a/drivers/extcon/extcon-arizona.c
+++ b/drivers/extcon/extcon-arizona.c
@@ -1049,6 +1049,42 @@ static void arizona_hpdet_work(struct work_struct *work)
 	mutex_unlock(&info->lock);
 }
 
+#define ARIZONA_HPDET_WAIT_COUNT 15
+#define ARIZONA_HPDET_WAIT_DELAY_MS 20
+
+static int arizona_hpdet_wait(struct arizona_extcon_info *info)
+{
+	struct arizona *arizona = info->arizona;
+	unsigned int val;
+	int i, ret;
+
+	for (i = 0; i < ARIZONA_HPDET_WAIT_COUNT; i++) {
+		ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_2,
+				  &val);
+		if (ret) {
+			dev_err(arizona->dev,
+				"Failed to read HPDET state: %d\n", ret);
+			return ret;
+		}
+
+		switch (info->hpdet_ip_version) {
+		case 0:
+			if (val & ARIZONA_HP_DONE)
+				return 0;
+			break;
+		default:
+			if (val & ARIZONA_HP_DONE_B)
+				return 0;
+			break;
+		}
+
+		msleep(ARIZONA_HPDET_WAIT_DELAY_MS);
+	}
+
+	dev_err(arizona->dev, "HPDET did not appear to complete\n");
+	return -ETIMEDOUT;
+}
+
 static irqreturn_t arizona_jackdet(int irq, void *data)
 {
 	struct arizona_extcon_info *info = data;
@@ -1155,6 +1191,15 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 					"Removal report failed: %d\n", ret);
 		}
 
+		/*
+		 * If the jack was removed during a headphone detection we
+		 * need to wait for the headphone detection to finish, as
+		 * it can not be aborted. We don't want to be able to start
+		 * a new headphone detection from a fresh insert until this
+		 * one is finished.
+		 */
+		arizona_hpdet_wait(info);
+
 		regmap_update_bits(arizona->regmap,
 				   ARIZONA_JACK_DETECT_DEBOUNCE,
 				   ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,
-- 
2.1.4

Re: [PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[Chanwoo Choi]

On 2017년 01월 25일 18:34, Charles Keepax wrote:
> As the HPDET can't be aborted mid way through we should not allow any new
> insertion to be processed until the previous HPDET has finished. It is very
> unlikely but with low enough debounce settings you could start a new HPDET
> before the old one has completed, which results in an erroneous reading.
> 
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> ---
> 
> Changes since v1:
>  - Added defines for the count and delay
>  - Added a comment to explain why we call arizona_hpdet_wait
> 
> Thanks,
> Charles
> 
>  drivers/extcon/extcon-arizona.c | 45 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> index ed78b7c..df98d84 100644
> --- a/drivers/extcon/extcon-arizona.c
> +++ b/drivers/extcon/extcon-arizona.c
> @@ -1049,6 +1049,42 @@ static void arizona_hpdet_work(struct work_struct *work)
>  	mutex_unlock(&info->lock);
>  }
>  
> +#define ARIZONA_HPDET_WAIT_COUNT 15
> +#define ARIZONA_HPDET_WAIT_DELAY_MS 20
> +
> +static int arizona_hpdet_wait(struct arizona_extcon_info *info)
> +{
> +	struct arizona *arizona = info->arizona;
> +	unsigned int val;
> +	int i, ret;
> +
> +	for (i = 0; i < ARIZONA_HPDET_WAIT_COUNT; i++) {
> +		ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_2,
> +				  &val);
> +		if (ret) {
> +			dev_err(arizona->dev,
> +				"Failed to read HPDET state: %d\n", ret);
> +			return ret;
> +		}
> +
> +		switch (info->hpdet_ip_version) {
> +		case 0:
> +			if (val & ARIZONA_HP_DONE)
> +				return 0;
> +			break;
> +		default:
> +			if (val & ARIZONA_HP_DONE_B)
> +				return 0;
> +			break;
> +		}
> +
> +		msleep(ARIZONA_HPDET_WAIT_DELAY_MS);
> +	}
> +
> +	dev_err(arizona->dev, "HPDET did not appear to complete\n");
> +	return -ETIMEDOUT;
> +}
> +
>  static irqreturn_t arizona_jackdet(int irq, void *data)
>  {
>  	struct arizona_extcon_info *info = data;
> @@ -1155,6 +1191,15 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
>  					"Removal report failed: %d\n", ret);
>  		}
>  
> +		/*
> +		 * If the jack was removed during a headphone detection we
> +		 * need to wait for the headphone detection to finish, as
> +		 * it can not be aborted. We don't want to be able to start
> +		 * a new headphone detection from a fresh insert until this
> +		 * one is finished.
> +		 */
> +		arizona_hpdet_wait(info);

If there is no necessary to handle the error return value,
I recommend that you better to use the dev_warn() instead of dev_err().

	dev_warn(arizona->dev, "HPDET did not appear to complete\n");


How about changing the debug level with dev_warn()?

> +
>  		regmap_update_bits(arizona->regmap,
>  				   ARIZONA_JACK_DETECT_DEBOUNCE,
>  				   ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[Charles Keepax]

On Wed, Jan 25, 2017 at 06:35:13PM +0900, Chanwoo Choi wrote:
> On 2017년 01월 25일 18:34, Charles Keepax wrote:
> > As the HPDET can't be aborted mid way through we should not allow any new
> > insertion to be processed until the previous HPDET has finished. It is very
> > unlikely but with low enough debounce settings you could start a new HPDET
> > before the old one has completed, which results in an erroneous reading.
> > 
> > Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> > ---
> > +		/*
> > +		 * If the jack was removed during a headphone detection we
> > +		 * need to wait for the headphone detection to finish, as
> > +		 * it can not be aborted. We don't want to be able to start
> > +		 * a new headphone detection from a fresh insert until this
> > +		 * one is finished.
> > +		 */
> > +		arizona_hpdet_wait(info);
> 
> If there is no necessary to handle the error return value,
> I recommend that you better to use the dev_warn() instead of dev_err().
> 
> 	dev_warn(arizona->dev, "HPDET did not appear to complete\n");
> 
> 
> How about changing the debug level with dev_warn()?
> 

Yeah can do.

Thanks,
Charles

Re: [PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[Chanwoo Choi]

Hi,

I modified some minor issue and added my comment on below.
After modified them by myself, Applied it. 

On 2017년 01월 25일 18:34, Charles Keepax wrote:
> As the HPDET can't be aborted mid way through we should not allow any new
> insertion to be processed until the previous HPDET has finished. It is very
> unlikely but with low enough debounce settings you could start a new HPDET
> before the old one has completed, which results in an erroneous reading.
> 
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> ---
> 
> Changes since v1:
>  - Added defines for the count and delay
>  - Added a comment to explain why we call arizona_hpdet_wait
> 
> Thanks,
> Charles
> 
>  drivers/extcon/extcon-arizona.c | 45 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> index ed78b7c..df98d84 100644
> --- a/drivers/extcon/extcon-arizona.c
> +++ b/drivers/extcon/extcon-arizona.c
> @@ -1049,6 +1049,42 @@ static void arizona_hpdet_work(struct work_struct *work)
>  	mutex_unlock(&info->lock);
>  }
>  
> +#define ARIZONA_HPDET_WAIT_COUNT 15
> +#define ARIZONA_HPDET_WAIT_DELAY_MS 20

Move these definitions on the top.

> +
> +static int arizona_hpdet_wait(struct arizona_extcon_info *info)
> +{
> +	struct arizona *arizona = info->arizona;
> +	unsigned int val;
> +	int i, ret;
> +
> +	for (i = 0; i < ARIZONA_HPDET_WAIT_COUNT; i++) {
> +		ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_2,
> +				  &val);

Remove the space indentation. I prefer to use only tab indentation.

> +		if (ret) {
> +			dev_err(arizona->dev,
> +				"Failed to read HPDET state: %d\n", ret);
> +			return ret;
> +		}
> +
> +		switch (info->hpdet_ip_version) {
> +		case 0:
> +			if (val & ARIZONA_HP_DONE)
> +				return 0;
> +			break;
> +		default:
> +			if (val & ARIZONA_HP_DONE_B)
> +				return 0;
> +			break;
> +		}
> +
> +		msleep(ARIZONA_HPDET_WAIT_DELAY_MS);
> +	}
> +
> +	dev_err(arizona->dev, "HPDET did not appear to complete\n");

Use dev_warn() instead of dev_err() because this message just
warn the current status.

> +	return -ETIMEDOUT;
> +}
> +
>  static irqreturn_t arizona_jackdet(int irq, void *data)
>  {
>  	struct arizona_extcon_info *info = data;
> @@ -1155,6 +1191,15 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
>  					"Removal report failed: %d\n", ret);
>  		}
>  
> +		/*
> +		 * If the jack was removed during a headphone detection we
> +		 * need to wait for the headphone detection to finish, as
> +		 * it can not be aborted. We don't want to be able to start
> +		 * a new headphone detection from a fresh insert until this
> +		 * one is finished.
> +		 */
> +		arizona_hpdet_wait(info);
> +
>  		regmap_update_bits(arizona->regmap,
>  				   ARIZONA_JACK_DETECT_DEBOUNCE,
>  				   ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v2] extcon: arizona: Wait for any running HPDETs to complete on jack removal

[Charles Keepax]

On Wed, Jan 25, 2017 at 06:48:06PM +0900, Chanwoo Choi wrote:
> Hi,
> 
> I modified some minor issue and added my comment on below.
> After modified them by myself, Applied it. 
> 
> On 2017년 01월 25일 18:34, Charles Keepax wrote:
> > As the HPDET can't be aborted mid way through we should not allow any new
> > insertion to be processed until the previous HPDET has finished. It is very
> > unlikely but with low enough debounce settings you could start a new HPDET
> > before the old one has completed, which results in an erroneous reading.
> > 
> > Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> > ---
> > +#define ARIZONA_HPDET_WAIT_COUNT 15
> > +#define ARIZONA_HPDET_WAIT_DELAY_MS 20
> 
> Move these definitions on the top.
> 

You can make this change if it is your preference, but generally
I feel this makes the code less clear. Previously you could
look at this bit of the code locally and clearly see what was
happening now the reader will need to spin all the way up to the
top of the file probably twice.

> > +
> > +static int arizona_hpdet_wait(struct arizona_extcon_info *info)
> > +{
> > +	struct arizona *arizona = info->arizona;
> > +	unsigned int val;
> > +	int i, ret;
> > +
> > +	for (i = 0; i < ARIZONA_HPDET_WAIT_COUNT; i++) {
> > +		ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_2,
> > +				  &val);
> 
> Remove the space indentation. I prefer to use only tab indentation.
> 

Again I don't mind, but my understanding was this was the
preferred style in the kernel and checkpatch --strict will warn
if you remove the spaces. It does also match the style of the
rest of the file itself.

Thanks,
Charles