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 */
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
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
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 */
On Friday 23 October 2015 16:53:26 WEN Pingbo wrote:
- Converting timeval to ktime_t, and there is no need to handle sec and
usec separately
- 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
On Friday, October 23, 2015 05:25 PM, Arnd Bergmann wrote:
On Friday 23 October 2015 16:53:26 WEN Pingbo wrote:
- Converting timeval to ktime_t, and there is no need to handle sec and
usec separately
- 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
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 */
On Friday 23 October 2015 19:29:39 WEN Pingbo wrote:
struct timeval is not y2038 safe, convert it to ktime_t, and there is no need to handle sec and usec separately
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
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:
- 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
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
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 */
-
Arnd Bergmann -
Pingbo Wen -
WEN Pingbo