[PATCH] hp_sdc: fixed y2038 problem

[PATCH] hp_sdc: fixed y2038 problem

[WEN Pingbo]

Two replacements happened in this patch:
    1. using timespec64 to prevent time overflow in 2038
    2. using ktime_get_ts64 to avoid wall time issues(leap second, etc)

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---
 drivers/input/serio/hp_sdc.c | 18 +++++++++---------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..76fb7fa 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	ktime_get_ts64(&hp_sdc.rtv);
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,13 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		struct timespec64 ts64;
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
+		ktime_get_ts64(&ts64);
+		if (ts64.tv_sec > hp_sdc.rtv.tv_sec)
+			ts64.tv_nsec += NSEC_PER_SEC;
 
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (ts64.tv_nsec - hp_sdc.rtv.tv_nsec > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +321,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       (s64)(ts64.tv_nsec - hp_sdc.rtv.tv_nsec));
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +551,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			ktime_get_ts64(&hp_sdc.rtv);
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..1535640 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	struct timespec64	rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

[PATCH] hp_sdc: fixed y2038 problem

[WEN Pingbo]

Two replacements happened in this patch:
    1. using timespec64 to prevent time overflow in 2038
    2. using ktime_get_ts64 to avoid wall time issues(leap second, etc)

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---
 drivers/input/serio/hp_sdc.c | 18 +++++++++---------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..76fb7fa 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	ktime_get_ts64(&hp_sdc.rtv);
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,13 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		struct timespec64 ts64;
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
+		ktime_get_ts64(&ts64);
+		if (ts64.tv_sec > hp_sdc.rtv.tv_sec)
+			ts64.tv_nsec += NSEC_PER_SEC;
 
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (ts64.tv_nsec - hp_sdc.rtv.tv_nsec > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +321,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       (s64)(ts64.tv_nsec - hp_sdc.rtv.tv_nsec));
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +551,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			ktime_get_ts64(&hp_sdc.rtv);
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..1535640 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	struct timespec64	rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

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Y2038@lists.linaro.org
https://lists.linaro.org/mailman/listinfo/y2038

Re: [Y2038] [PATCH] hp_sdc: fixed y2038 problem

[Arnd Bergmann]

On Sunday 18 October 2015 17:44:19 WEN Pingbo wrote:
> Two replacements happened in this patch:
>     1. using timespec64 to prevent time overflow in 2038
>     2. using ktime_get_ts64 to avoid wall time issues(leap second, etc)
> 
> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
> 

The patch looks correct, but I think this could be written a little
simpler and clearer using ktime_get() or ktime_getns().

	Arnd

Re: [Y2038] [PATCH] hp_sdc: fixed y2038 problem

[Pingbo Wen]

On Monday, October 19, 2015 05:01 PM, Arnd Bergmann wrote:
> On Sunday 18 October 2015 17:44:19 WEN Pingbo wrote:
>> Two replacements happened in this patch:
>>     1. using timespec64 to prevent time overflow in 2038
>>     2. using ktime_get_ts64 to avoid wall time issues(leap second, etc)
>>
>> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
>>
> 
> The patch looks correct, but I think this could be written a little
> simpler and clearer using ktime_get() or ktime_getns().
> 

That make sense, Maybe it can save a sec shift operation. I will check it later.

Pingbo

[PATCH V2] hp_sdc: fixed y2038 problem

[WEN Pingbo]

1. Converting timeval to ktime_t, and there is no need to handle sec and
usec separately

2. hp_sdc.rtv is only used for time diff, monotonic time is better here

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---
 drivers/input/serio/hp_sdc.c | 16 ++++++----------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..8ef82ee 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	hp_sdc.rtv = ktime_get();
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,9 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		ktime_t time_diff = ktime_sub(ktime_get(), hp_sdc.rtv);
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
-
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (time_diff.tv64 > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +317,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       time_diff.tv64);
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +547,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			hp_sdc.rtv = ktime_get();
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..348a9b5 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	ktime_t		rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

Re: [Y2038] [PATCH V2] hp_sdc: fixed y2038 problem

[Arnd Bergmann]

On Friday 23 October 2015 16:53:26 WEN Pingbo wrote:
> 1. Converting timeval to ktime_t, and there is no need to handle sec and
> usec separately
> 
> 2. hp_sdc.rtv is only used for time diff, monotonic time is better here
> 
> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
> ---

This version is still correct and looks better than the first version, but
I'd still like you to improve some details:

- read some other changelogs and follow the common style. In particular,
  in the subject line say /what/ you do ("e.g. use ktime_get instead of
  do_gettimeofday",  or "avoid using struct timespec") instead of /why/,
  but then explain in the changelog text what is wrong with the current
  version and why it gets changed like this.

- Below the '---', add a short list of things you have changed since
  the previous versions. This part will not get copied into the git
  history.

> -		do_gettimeofday(&tv);
> -		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
> -			tv.tv_usec += USEC_PER_SEC;
> -
> -		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
> +		if (time_diff.tv64 > HP_SDC_MAX_REG_DELAY) {
>  			hp_sdc_transaction *curr;
>  			uint8_t tmp;
>  
> -			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
> -			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
> +			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
> +			       time_diff.tv64);
>  			curr->idx += hp_sdc.rqty;
>  			hp_sdc.rqty = 0;
>  			tmp = curr->seq[curr->actidx];

A tiny style comment here: please use ktime_to_ns() to extract the
nanoseconds out of the ktime_t type rather than accessing the tv64
member directly.

	Arnd

Re: [Y2038] [PATCH V2] hp_sdc: fixed y2038 problem

[Pingbo Wen]

On Friday, October 23, 2015 05:25 PM, Arnd Bergmann wrote:
> On Friday 23 October 2015 16:53:26 WEN Pingbo wrote:
>> 1. Converting timeval to ktime_t, and there is no need to handle sec and
>> usec separately
>>
>> 2. hp_sdc.rtv is only used for time diff, monotonic time is better here
>>
>> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
>> ---
> 
> This version is still correct and looks better than the first version, but
> I'd still like you to improve some details:
> 
> - read some other changelogs and follow the common style. In particular,
>   in the subject line say /what/ you do ("e.g. use ktime_get instead of
>   do_gettimeofday",  or "avoid using struct timespec") instead of /why/,
>   but then explain in the changelog text what is wrong with the current
>   version and why it gets changed like this.
> 
> - Below the '---', add a short list of things you have changed since
>   the previous versions. This part will not get copied into the git
>   history.
> 

Ok, I will fix this in the next version.

>> -		do_gettimeofday(&tv);
>> -		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
>> -			tv.tv_usec += USEC_PER_SEC;
>> -
>> -		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
>> +		if (time_diff.tv64 > HP_SDC_MAX_REG_DELAY) {
>>  			hp_sdc_transaction *curr;
>>  			uint8_t tmp;
>>  
>> -			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
>> -			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
>> +			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
>> +			       time_diff.tv64);
>>  			curr->idx += hp_sdc.rqty;
>>  			hp_sdc.rqty = 0;
>>  			tmp = curr->seq[curr->actidx];
> 
> A tiny style comment here: please use ktime_to_ns() to extract the
> nanoseconds out of the ktime_t type rather than accessing the tv64
> member directly.

Same here.

Thank you
Pingbo

> 
> 	Arnd
> 

Re: [PATCH V2] hp_sdc: fixed y2038 problem

[Pingbo Wen]

On Friday, October 23, 2015 05:25 PM, Arnd Bergmann wrote:
> On Friday 23 October 2015 16:53:26 WEN Pingbo wrote:
>> 1. Converting timeval to ktime_t, and there is no need to handle sec and
>> usec separately
>>
>> 2. hp_sdc.rtv is only used for time diff, monotonic time is better here
>>
>> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
>> ---
> 
> This version is still correct and looks better than the first version, but
> I'd still like you to improve some details:
> 
> - read some other changelogs and follow the common style. In particular,
>   in the subject line say /what/ you do ("e.g. use ktime_get instead of
>   do_gettimeofday",  or "avoid using struct timespec") instead of /why/,
>   but then explain in the changelog text what is wrong with the current
>   version and why it gets changed like this.
> 
> - Below the '---', add a short list of things you have changed since
>   the previous versions. This part will not get copied into the git
>   history.
> 

Ok, I will fix this in the next version.

>> -		do_gettimeofday(&tv);
>> -		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
>> -			tv.tv_usec += USEC_PER_SEC;
>> -
>> -		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
>> +		if (time_diff.tv64 > HP_SDC_MAX_REG_DELAY) {
>>  			hp_sdc_transaction *curr;
>>  			uint8_t tmp;
>>  
>> -			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
>> -			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
>> +			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
>> +			       time_diff.tv64);
>>  			curr->idx += hp_sdc.rqty;
>>  			hp_sdc.rqty = 0;
>>  			tmp = curr->seq[curr->actidx];
> 
> A tiny style comment here: please use ktime_to_ns() to extract the
> nanoseconds out of the ktime_t type rather than accessing the tv64
> member directly.

Same here.

Thank you
Pingbo

> 
> 	Arnd
> 
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[PATCH V3] hp_sdc: convert struct timeval to ktime_t

[WEN Pingbo]

1. struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately

2. hp_sdc.rtv is only used for time diff, monotonic time is better here

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---

Version 2:
	Using ktime_t instead of struct timespec64
Version 3:
	Commit msg adjustment, and using ktime_to_ns to extract nsecs 

 drivers/input/serio/hp_sdc.c | 16 ++++++----------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..17e3725 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	hp_sdc.rtv = ktime_get();
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,9 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		ktime_t time_diff = ktime_sub(ktime_get(), hp_sdc.rtv);
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
-
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (ktime_to_ns(time_diff) > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +317,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       ktime_to_ns(time_diff));
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +547,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			hp_sdc.rtv = ktime_get();
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..348a9b5 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	ktime_t		rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

Re: [PATCH V3] hp_sdc: convert struct timeval to ktime_t

[Arnd Bergmann]

On Friday 23 October 2015 19:29:39 WEN Pingbo wrote:
> 1. struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately
> 
> 2. hp_sdc.rtv is only used for time diff, monotonic time is better here
> 
> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
> ---
> 
> Version 2:
>         Using ktime_t instead of struct timespec64
> Version 3:
>         Commit msg adjustment, and using ktime_to_ns to extract nsecs 
> 

The patch looks good now, but the changelog still needs a tiny bit of
work. First of all, your line wrapping is off, please start a new line
after around 70 characters as you do in an email.

Also, we don't normally have enumerated lists in a changelog, just use
normal text. The best changelogs typically have three paragraphs:

The first paragraph describes what the driver currently does. For really
obvious cases, this can be combined with the second paragraph.

The second paragraph explains why that is bad. This is where you can
mention the monotonic time vs real time issue and say whether we
just want the timeval removed to fix the kernel in general or whether
this particular driver is broken.

The third paragraph explains what the patch does to resolve the issue
described in the second one. This is also where you can list other
approaches that would have solved the problem, and why you picked on
over the others.

	Arnd

Re: [PATCH V3] hp_sdc: convert struct timeval to ktime_t

[Arnd Bergmann]

On Friday 23 October 2015 19:29:39 WEN Pingbo wrote:
> 1. struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately
> 
> 2. hp_sdc.rtv is only used for time diff, monotonic time is better here
> 
> Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
> ---
> 
> Version 2:
>         Using ktime_t instead of struct timespec64
> Version 3:
>         Commit msg adjustment, and using ktime_to_ns to extract nsecs 
> 

The patch looks good now, but the changelog still needs a tiny bit of
work. First of all, your line wrapping is off, please start a new line
after around 70 characters as you do in an email.

Also, we don't normally have enumerated lists in a changelog, just use
normal text. The best changelogs typically have three paragraphs:

The first paragraph describes what the driver currently does. For really
obvious cases, this can be combined with the second paragraph.

The second paragraph explains why that is bad. This is where you can
mention the monotonic time vs real time issue and say whether we
just want the timeval removed to fix the kernel in general or whether
this particular driver is broken.

The third paragraph explains what the patch does to resolve the issue
described in the second one. This is also where you can list other
approaches that would have solved the problem, and why you picked on
over the others.

	Arnd
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Re: [PATCH V3] hp_sdc: convert struct timeval to ktime_t

[Pingbo Wen]

> 在 2015年10月23日，19:45，Arnd Bergmann <arnd@arndb.de> 写道：
> 
> On Friday 23 October 2015 19:29:39 WEN Pingbo wrote:
>> 1. struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately
>> 
>> 
> 
> The patch looks good now, but the changelog still needs a tiny bit of
> work. First of all, your line wrapping is off, please start a new line
> after around 70 characters as you do in an email.
> 

Well, little fault:)
Will be fixed in next version.

> Also, we don't normally have enumerated lists in a changelog, just use
> normal text. The best changelogs typically have three paragraphs:
> 
> The first paragraph describes what the driver currently does. For really
> obvious cases, this can be combined with the second paragraph.
> 
> The second paragraph explains why that is bad. This is where you can
> mention the monotonic time vs real time issue and say whether we
> just want the timeval removed to fix the kernel in general or whether
> this particular driver is broken.
> 
> The third paragraph explains what the patch does to resolve the issue
> described in the second one. This is also where you can list other
> approaches that would have solved the problem, and why you picked on
> over the others.

Do we really need this in ChangeLog? Commit msg already states this. I think
the purpose of ChangeLog is let people know the main difference of two
version patch at a glance, and the ‘what’ and ‘why’ should be placed in
commit msg.

Pingbo

Re: [PATCH V3] hp_sdc: convert struct timeval to ktime_t

[Pingbo Wen]

> 在 2015年10月23日，19:45，Arnd Bergmann <arnd@arndb.de> 写道：
> 
> On Friday 23 October 2015 19:29:39 WEN Pingbo wrote:
>> 1. struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately
>> 
>> 
> 
> The patch looks good now, but the changelog still needs a tiny bit of
> work. First of all, your line wrapping is off, please start a new line
> after around 70 characters as you do in an email.
> 

Well, little fault:)
Will be fixed in next version.

> Also, we don't normally have enumerated lists in a changelog, just use
> normal text. The best changelogs typically have three paragraphs:
> 
> The first paragraph describes what the driver currently does. For really
> obvious cases, this can be combined with the second paragraph.
> 
> The second paragraph explains why that is bad. This is where you can
> mention the monotonic time vs real time issue and say whether we
> just want the timeval removed to fix the kernel in general or whether
> this particular driver is broken.
> 
> The third paragraph explains what the patch does to resolve the issue
> described in the second one. This is also where you can list other
> approaches that would have solved the problem, and why you picked on
> over the others.

Do we really need this in ChangeLog? Commit msg already states this. I think
the purpose of ChangeLog is let people know the main difference of two
version patch at a glance, and the ‘what’ and ‘why’ should be placed in
commit msg.

Pingbo--
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Re: [PATCH V3] hp_sdc: convert struct timeval to ktime_t

[Arnd Bergmann]

On Friday 23 October 2015 20:19:46 Pingbo Wen wrote:
> 
> > Also, we don't normally have enumerated lists in a changelog, just use
> > normal text. The best changelogs typically have three paragraphs:
> > 
> > The first paragraph describes what the driver currently does. For really
> > obvious cases, this can be combined with the second paragraph.
> > 
> > The second paragraph explains why that is bad. This is where you can
> > mention the monotonic time vs real time issue and say whether we
> > just want the timeval removed to fix the kernel in general or whether
> > this particular driver is broken.
> > 
> > The third paragraph explains what the patch does to resolve the issue
> > described in the second one. This is also where you can list other
> > approaches that would have solved the problem, and why you picked on
> > over the others.
> 
> Do we really need this in ChangeLog? Commit msg already states this. I think
> the purpose of ChangeLog is let people know the main difference of two
> version patch at a glance, and the ‘what’ and ‘why’ should be placed in
> commit msg.
> 

I was using the terms changelog and commit message interchangeably, sorry
for being unclear. I meant the part above the --- line. The revision
history you have below the --- line looks good here.

	Arnd

[PATCH V4] hp_sdc: convert struct timeval to ktime_t

[WEN Pingbo]

struct timeval is not y2038 safe, convert it to ktime_t,
and there is no need to handle sec and usec separately

And since hp_sdc.rtv is only used for time diff, monotonic time
is better here

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---

Version 2:
	Using ktime_t instead of struct timespec64
Version 3:
	Commit msg adjustment, and using ktime_to_ns to extract nsecs 
Version 4:
	Correct commit msg format

 drivers/input/serio/hp_sdc.c | 16 ++++++----------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..17e3725 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	hp_sdc.rtv = ktime_get();
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,9 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		ktime_t time_diff = ktime_sub(ktime_get(), hp_sdc.rtv);
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
-
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (ktime_to_ns(time_diff) > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +317,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       ktime_to_ns(time_diff));
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +547,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			hp_sdc.rtv = ktime_get();
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..348a9b5 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	ktime_t		rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

[PATCH V4] hp_sdc: convert struct timeval to ktime_t

[WEN Pingbo]

struct timeval is not y2038 safe, convert it to ktime_t,
and there is no need to handle sec and usec separately

And since hp_sdc.rtv is only used for time diff, monotonic time
is better here

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
---

Version 2:
	Using ktime_t instead of struct timespec64
Version 3:
	Commit msg adjustment, and using ktime_to_ns to extract nsecs 
Version 4:
	Correct commit msg format

 drivers/input/serio/hp_sdc.c | 16 ++++++----------
 include/linux/hp_sdc.h       |  6 +++---
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/input/serio/hp_sdc.c b/drivers/input/serio/hp_sdc.c
index 852858e..17e3725 100644
--- a/drivers/input/serio/hp_sdc.c
+++ b/drivers/input/serio/hp_sdc.c
@@ -193,7 +193,7 @@ static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 	curr->seq[curr->idx++] = status;
 	curr->seq[curr->idx++] = data;
 	hp_sdc.rqty -= 2;
-	do_gettimeofday(&hp_sdc.rtv);
+	hp_sdc.rtv = ktime_get();
 
 	if (hp_sdc.rqty <= 0) {
 		/* All data has been gathered. */
@@ -306,13 +306,9 @@ static void hp_sdc_tasklet(unsigned long foo)
 	write_lock_irq(&hp_sdc.rtq_lock);
 
 	if (hp_sdc.rcurr >= 0) {
-		struct timeval tv;
+		ktime_t time_diff = ktime_sub(ktime_get(), hp_sdc.rtv);
 
-		do_gettimeofday(&tv);
-		if (tv.tv_sec > hp_sdc.rtv.tv_sec)
-			tv.tv_usec += USEC_PER_SEC;
-
-		if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
+		if (ktime_to_ns(time_diff) > HP_SDC_MAX_REG_DELAY) {
 			hp_sdc_transaction *curr;
 			uint8_t tmp;
 
@@ -321,8 +317,8 @@ static void hp_sdc_tasklet(unsigned long foo)
 			 * we'll need to figure out a way to communicate
 			 * it back to the application. and be less verbose.
 			 */
-			printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
-			       (int)(tv.tv_usec - hp_sdc.rtv.tv_usec));
+			printk(KERN_WARNING PREFIX "read timeout (%llins)!\n",
+			       ktime_to_ns(time_diff));
 			curr->idx += hp_sdc.rqty;
 			hp_sdc.rqty = 0;
 			tmp = curr->seq[curr->actidx];
@@ -551,7 +547,7 @@ unsigned long hp_sdc_put(void)
 
 			/* Start a new read */
 			hp_sdc.rqty = curr->seq[curr->idx];
-			do_gettimeofday(&hp_sdc.rtv);
+			hp_sdc.rtv = ktime_get();
 			curr->idx++;
 			/* Still need to lock here in case of spurious irq. */
 			write_lock_irq(&hp_sdc.rtq_lock);
diff --git a/include/linux/hp_sdc.h b/include/linux/hp_sdc.h
index d392975..348a9b5 100644
--- a/include/linux/hp_sdc.h
+++ b/include/linux/hp_sdc.h
@@ -47,9 +47,9 @@
 #endif
 
 
-/* No 4X status reads take longer than this (in usec).
+/* No 4X status reads take longer than this (in nsec).
  */
-#define HP_SDC_MAX_REG_DELAY 20000
+#define HP_SDC_MAX_REG_DELAY 20000000
 
 typedef void (hp_sdc_irqhook) (int irq, void *dev_id, 
 			       uint8_t status, uint8_t data);
@@ -281,7 +281,7 @@ typedef struct {
 	hp_sdc_transaction *tq[HP_SDC_QUEUE_LEN]; /* All pending read/writes */
 
 	int		rcurr, rqty;	/* Current read transact in process */
-	struct timeval	rtv;		/* Time when current read started */
+	ktime_t		rtv;		/* Time when current read started */
 	int		wcurr;		/* Current write transact in process */
 
 	int		dev_err;	/* carries status from registration */
-- 
1.9.1

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