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extcon: arizona: Wait for any running HPDETs to complete on jack removal

PATCH Superseded Charles Keepax 2 participants 3 messages Jan 24, 2017 – Jan 25, 2017 External connector subsystem (extcon)

v1 of 2 Superseded Latest is v2 →

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Charles Keepax

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#0 lore raw

PATCH 1/1 extcon: arizona: Wait for any running HPDETs to complete on jack removal

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 <[email protected]>
---
 drivers/extcon/extcon-arizona.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
drivers/extcon/extcon-arizona.c +35 -0
index ed78b7c..218e378 100644
@@ -1049,6 +1049,39 @@ static void arizona_hpdet_work(struct work_struct *work)
 	mutex_unlock(&info->lock);
 }
 
+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 < 15; 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(20);
+	}
+
+	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 +1188,8 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 					"Removal report failed: %d\n", ret);
 		}
 
+		arizona_hpdet_wait(info);
+
 		regmap_update_bits(arizona->regmap,
 				   ARIZONA_JACK_DETECT_DEBOUNCE,
 				   ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,
Signature · 1 line
2.1.4
maintainer
#1 lore raw

Hi Charles,

Quoted 15 lines · 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 <[email protected]>
---
 drivers/extcon/extcon-arizona.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
drivers/extcon/extcon-arizona.c +0 -0
index ed78b7c..218e378 100644

drivers/extcon/extcon-arizona.c static void arizona_hpdet_work(struct work_struct *work) · line 1058

Quoted 10 lines
drivers/extcon/extcon-arizona.c +7 -0
@@ -1049,6 +1049,39 @@ static void arizona_hpdet_work(struct work_struct *work)
 	mutex_unlock(&info->lock);
 }
 
+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 < 15; i++) {

I recommend that you define the separate constant definition instead of using interger value (15) directly as following:

	#define HPDET_WAIT_COUNT	15
Quoted 10 lines
drivers/extcon/extcon-arizona.c +10 -0
+		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:

drivers/extcon/extcon-arizona.c static void arizona_hpdet_work(struct work_struct *work) · line 1078

Quoted 10 lines
drivers/extcon/extcon-arizona.c +10 -0
+			if (val & ARIZONA_HP_DONE)
+				return 0;
+			break;
+		default:
+			if (val & ARIZONA_HP_DONE_B)
+				return 0;
+			break;
+		}
+
+		msleep(20);

ditto.

	#define HPDET_WAIT_DELAY_MS	20

drivers/extcon/extcon-arizona.c static irqreturn_t arizona_jackdet(int irq, void *data) · line 1190

Quoted 13 lines
drivers/extcon/extcon-arizona.c +6 -0
+	}
+
+	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 +1188,8 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 					"Removal report failed: %d\n", ret);
 		}

Sometimes I met this similiar case on specific h/w. I agree to add some delay according to the h/w. So, you better to add the detailed comment before calling the arizona_hpdet_wait() to make it easy to understand why it is necessary.

drivers/extcon/extcon-arizona.c static irqreturn_t arizona_jackdet(int irq, void *data) · line 1191

Quoted 1 line
drivers/extcon/extcon-arizona.c +1 -0
+		arizona_hpdet_wait(info);

Is not necessary to check the return value of this call? When arizona_hpdet_wait() return the -ETIMEDOUT, Does not this error affect the next some code?

Quoted 6 lines
drivers/extcon/extcon-arizona.c +1 -0
+
 
 		regmap_update_bits(arizona->regmap,
 				   ARIZONA_JACK_DETECT_DEBOUNCE,

ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,

Signature · 3 lines
Best Regards,
Chanwoo Choi
Samsung Electronics
author
#2 lore raw
Quoted 57 lines · Chanwoo Choi

Hi Charles,

Quoted 15 lines · 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 <[email protected]>
---
 drivers/extcon/extcon-arizona.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
drivers/extcon/extcon-arizona.c +0 -0
index ed78b7c..218e378 100644

drivers/extcon/extcon-arizona.c static void arizona_hpdet_work(struct work_struct *work) · line 1058

Quoted 10 lines
drivers/extcon/extcon-arizona.c +7 -0
@@ -1049,6 +1049,39 @@ static void arizona_hpdet_work(struct work_struct *work)
 	mutex_unlock(&info->lock);
 }
 
+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 < 15; i++) {

I recommend that you define the separate constant definition instead of using interger value (15) directly as following:

	#define HPDET_WAIT_COUNT	15
Quoted 10 lines
drivers/extcon/extcon-arizona.c +10 -0
+		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:

drivers/extcon/extcon-arizona.c static void arizona_hpdet_work(struct work_struct *work) · line 1078

Quoted 10 lines
drivers/extcon/extcon-arizona.c +10 -0
+			if (val & ARIZONA_HP_DONE)
+				return 0;
+			break;
+		default:
+			if (val & ARIZONA_HP_DONE_B)
+				return 0;
+			break;
+		}
+
+		msleep(20);

ditto.

Quoted 2 lines
	#define HPDET_WAIT_DELAY_MS	20

Yeah can do.

Quoted 20 lines

drivers/extcon/extcon-arizona.c static irqreturn_t arizona_jackdet(int irq, void *data) · line 1190

Quoted 13 lines
drivers/extcon/extcon-arizona.c +6 -0
+	}
+
+	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 +1188,8 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 					"Removal report failed: %d\n", ret);
 		}

Sometimes I met this similiar case on specific h/w. I agree to add some delay according to the h/w. So, you better to add the detailed comment before calling the arizona_hpdet_wait() to make it easy to understand why it is necessary.

Quoted 2 lines

drivers/extcon/extcon-arizona.c static irqreturn_t arizona_jackdet(int irq, void *data) · line 1191

Quoted 1 line
drivers/extcon/extcon-arizona.c +1 -0
+		arizona_hpdet_wait(info);

No problem to add a comment.

Quoted 4 lines

Is not necessary to check the return value of this call? When arizona_hpdet_wait() return the -ETIMEDOUT, Does not this error affect the next some code?

I included a return value for completeness sake and incase the function gets reused in other places in the future. But at that point I don't think there is really any action we can take if that call fails, that part of the code relates to the jack being removed so we still need to take all those actions. We can only really log that the failure happened in the kernel log which it already does.

Thanks,
Charles

Quoted 10 lines
Quoted 6 lines
drivers/extcon/extcon-arizona.c +1 -0
+
 
 		regmap_update_bits(arizona->regmap,
 				   ARIZONA_JACK_DETECT_DEBOUNCE,

ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,

Signature · 3 lines
Best Regards,
Chanwoo Choi
Samsung Electronics