Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-24 Thread Richard Cochran 
On Mon, Jul 24, 2017 at 07:34:38PM -0500, Grygorii Strashko wrote:
> Below if pure TBD/RFC version of patch which add kthread worker to PTP core.
> I'm sending it to get you opinion about implementation in general, before 
> continue with more changes. Pls, take a look if you have time?
> - are you ok with names (API, callbacks, ptp structs members)?

The API and naming looks good to me.
 
> I can prepare, update and resend proper patches tom if feedback is positive.

Please do.

> I also can convert dp83640 driver to use new feature, but I can't test it.

No need for that.  It would be enough to have cpts as the first user
and example.
 
> + if (ptp->info->do_aux_work) {
> + struct sched_param param = {
> + .sched_priority = MAX_RT_PRIO - 1 };
> +
> + kthread_init_delayed_work(>aux_work, ptp_aux_kworker);
> + ptp->kworker = kthread_create_worker(0, info->name);
> + if (IS_ERR(ptp->kworker)) {
> + pr_err("failed to create ptp aux_worker task %ld\n",
> +PTR_ERR(ptp->kworker));
> + return ERR_CAST(ptp->kworker);
> + }
> + err = sched_setscheduler_nocheck(ptp->kworker->task,
> +  SCHED_FIFO, );

I think we should not hard code the scheduler and priority here but
rather leave it to the sysadmin to configure these using chrt(1).
After all, a normal work item is has served just in many situations.

> + if (err)
> + pr_err("sched_setscheduler_nocheck err %d\n", err);
> + }
> +
>   err = ptp_populate_pin_groups(ptp);
>   if (err)
>   goto no_pin_groups;
> @@ -274,6 +305,9 @@ int ptp_clock_unregister(struct ptp_clock *ptp)
>   ptp->defunct = 1;
>   wake_up_interruptible(>tsev_wq);
>  
> + kthread_cancel_delayed_work_sync(>aux_work);
> + kthread_destroy_worker(ptp->kworker);

These can't be called unconditionally.

>   /* Release the clock's resources. */
>   if (ptp->pps_source)
>   pps_unregister_source(ptp->pps_source);

Thanks,
Richard

Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-24 Thread Richard Cochran 
On Mon, Jul 24, 2017 at 07:34:38PM -0500, Grygorii Strashko wrote:
> Below if pure TBD/RFC version of patch which add kthread worker to PTP core.
> I'm sending it to get you opinion about implementation in general, before 
> continue with more changes. Pls, take a look if you have time?
> - are you ok with names (API, callbacks, ptp structs members)?

The API and naming looks good to me.
 
> I can prepare, update and resend proper patches tom if feedback is positive.

Please do.

> I also can convert dp83640 driver to use new feature, but I can't test it.

No need for that.  It would be enough to have cpts as the first user
and example.
 
> + if (ptp->info->do_aux_work) {
> + struct sched_param param = {
> + .sched_priority = MAX_RT_PRIO - 1 };
> +
> + kthread_init_delayed_work(>aux_work, ptp_aux_kworker);
> + ptp->kworker = kthread_create_worker(0, info->name);
> + if (IS_ERR(ptp->kworker)) {
> + pr_err("failed to create ptp aux_worker task %ld\n",
> +PTR_ERR(ptp->kworker));
> + return ERR_CAST(ptp->kworker);
> + }
> + err = sched_setscheduler_nocheck(ptp->kworker->task,
> +  SCHED_FIFO, );

I think we should not hard code the scheduler and priority here but
rather leave it to the sysadmin to configure these using chrt(1).
After all, a normal work item is has served just in many situations.

> + if (err)
> + pr_err("sched_setscheduler_nocheck err %d\n", err);
> + }
> +
>   err = ptp_populate_pin_groups(ptp);
>   if (err)
>   goto no_pin_groups;
> @@ -274,6 +305,9 @@ int ptp_clock_unregister(struct ptp_clock *ptp)
>   ptp->defunct = 1;
>   wake_up_interruptible(>tsev_wq);
>  
> + kthread_cancel_delayed_work_sync(>aux_work);
> + kthread_destroy_worker(ptp->kworker);

These can't be called unconditionally.

>   /* Release the clock's resources. */
>   if (ptp->pps_source)
>   pps_unregister_source(ptp->pps_source);

Thanks,
Richard

Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-24 Thread Grygorii Strashko 
Hi Richard,

On 07/22/2017 12:29 AM, Richard Cochran wrote:
> On Fri, Jul 21, 2017 at 06:49:42PM -0500, Grygorii Strashko wrote:
>> There could be significant delay in CPTS work schedule under high system
>> load and on -RT which could cause CPTS misbehavior due to internal counter
>> overflow. Usage of own kthread_worker allows to avoid such kind of issues
>> and makes it possible to tune priority of CPTS kthread_worker thread on -RT
>> (thread name "cpts").
> 
> I have also seen excessive delays in the time stamp work from the
> dp83640 under certain loads.  Can we please implement this time stamp
> kthread_worker in the PHC subsystem?  That way, the facility can be
> used by other drivers without code duplication.

Below if pure TBD/RFC version of patch which add kthread worker to PTP core.
I'm sending it to get you opinion about implementation in general, before 
continue with more changes. Pls, take a look if you have time?
- are you ok with names (API, callbacks, ptp structs members)?

I can prepare, update and resend proper patches tom if feedback is positive.
I also can convert dp83640 driver to use new feature, but I can't test it.

>From 48212c4564ae38d633d95723b1f4616dee195b47 Mon Sep 17 00:00:00 2001
From: Grygorii Strashko 
Date: Mon, 24 Jul 2017 19:19:50 -0500
Subject: [PATCH] [rfc] ptp: add auxiliary worker

Add auxiliary kthread worker to PTP core so drivers can
re-use it and benefit from common implementation which is RT
friendly... TBD

Signed-off-by: Grygorii Strashko 
---
 drivers/net/ethernet/ti/cpts.c   | 53 +++-
 drivers/net/ethernet/ti/cpts.h   |  2 --
 drivers/ptp/ptp_clock.c  | 42 +++
 drivers/ptp/ptp_private.h|  3 +++
 include/linux/ptp_clock_kernel.h | 15 
 5 files changed, 80 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 746dd1d..e05a1b4 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -280,23 +280,9 @@ static int cpts_ptp_enable(struct ptp_clock_info *ptp,
return -EOPNOTSUPP;
 }
 
-static struct ptp_clock_info cpts_info = {
-   .owner  = THIS_MODULE,
-   .name   = "CTPS timer",
-   .max_adj= 100,
-   .n_ext_ts   = 0,
-   .n_pins = 0,
-   .pps= 0,
-   .adjfreq= cpts_ptp_adjfreq,
-   .adjtime= cpts_ptp_adjtime,
-   .gettime64  = cpts_ptp_gettime,
-   .settime64  = cpts_ptp_settime,
-   .enable = cpts_ptp_enable,
-};
-
-static void cpts_overflow_check(struct kthread_work *work)
+static long cpts_overflow_check(struct ptp_clock_info *ptp)
 {
-   struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
+   struct cpts *cpts = container_of(ptp, struct cpts, info);
unsigned long delay = cpts->ov_check_period;
struct timespec64 ts;
unsigned long flags;
@@ -309,9 +295,24 @@ static void cpts_overflow_check(struct kthread_work *work)
spin_unlock_irqrestore(>lock, flags);
 
pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
-   kthread_queue_delayed_work(cpts->kworker, >overflow_work, delay);
+   return (long)delay;
 }
 
+static struct ptp_clock_info cpts_info = {
+   .owner  = THIS_MODULE,
+   .name   = "CTPS timer",
+   .max_adj= 100,
+   .n_ext_ts   = 0,
+   .n_pins = 0,
+   .pps= 0,
+   .adjfreq= cpts_ptp_adjfreq,
+   .adjtime= cpts_ptp_adjtime,
+   .gettime64  = cpts_ptp_gettime,
+   .settime64  = cpts_ptp_settime,
+   .enable = cpts_ptp_enable,
+   .do_aux_work= cpts_overflow_check,
+};
+
 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
  u16 ts_seqid, u8 ts_msgtype)
 {
@@ -392,8 +393,7 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff 
*skb, int ev_type)
/* get the timestamp for timeouts */
skb_cb->tmo = jiffies + msecs_to_jiffies(100);
__skb_queue_tail(>txq, skb);
-   kthread_mod_delayed_work(cpts->kworker,
->overflow_work, 0);
+   ptp_schedule_worker(cpts->clock, 0);
}
spin_unlock_irqrestore(>lock, flags);
 
@@ -457,8 +457,7 @@ int cpts_register(struct cpts *cpts)
}
cpts->phc_index = ptp_clock_index(cpts->clock);
 
-   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
-  cpts->ov_check_period);
+   ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
return 0;
 
 err_ptp:
@@ -472,8 +471,6 @@ void cpts_unregister(struct cpts *cpts)
if (WARN_ON(!cpts->clock))
return;
 
-

Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-24 Thread Grygorii Strashko 
Hi Richard,

On 07/22/2017 12:29 AM, Richard Cochran wrote:
> On Fri, Jul 21, 2017 at 06:49:42PM -0500, Grygorii Strashko wrote:
>> There could be significant delay in CPTS work schedule under high system
>> load and on -RT which could cause CPTS misbehavior due to internal counter
>> overflow. Usage of own kthread_worker allows to avoid such kind of issues
>> and makes it possible to tune priority of CPTS kthread_worker thread on -RT
>> (thread name "cpts").
> 
> I have also seen excessive delays in the time stamp work from the
> dp83640 under certain loads.  Can we please implement this time stamp
> kthread_worker in the PHC subsystem?  That way, the facility can be
> used by other drivers without code duplication.

Below if pure TBD/RFC version of patch which add kthread worker to PTP core.
I'm sending it to get you opinion about implementation in general, before 
continue with more changes. Pls, take a look if you have time?
- are you ok with names (API, callbacks, ptp structs members)?

I can prepare, update and resend proper patches tom if feedback is positive.
I also can convert dp83640 driver to use new feature, but I can't test it.

>From 48212c4564ae38d633d95723b1f4616dee195b47 Mon Sep 17 00:00:00 2001
From: Grygorii Strashko 
Date: Mon, 24 Jul 2017 19:19:50 -0500
Subject: [PATCH] [rfc] ptp: add auxiliary worker

Add auxiliary kthread worker to PTP core so drivers can
re-use it and benefit from common implementation which is RT
friendly... TBD

Signed-off-by: Grygorii Strashko 
---
 drivers/net/ethernet/ti/cpts.c   | 53 +++-
 drivers/net/ethernet/ti/cpts.h   |  2 --
 drivers/ptp/ptp_clock.c  | 42 +++
 drivers/ptp/ptp_private.h|  3 +++
 include/linux/ptp_clock_kernel.h | 15 
 5 files changed, 80 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 746dd1d..e05a1b4 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -280,23 +280,9 @@ static int cpts_ptp_enable(struct ptp_clock_info *ptp,
return -EOPNOTSUPP;
 }
 
-static struct ptp_clock_info cpts_info = {
-   .owner  = THIS_MODULE,
-   .name   = "CTPS timer",
-   .max_adj= 100,
-   .n_ext_ts   = 0,
-   .n_pins = 0,
-   .pps= 0,
-   .adjfreq= cpts_ptp_adjfreq,
-   .adjtime= cpts_ptp_adjtime,
-   .gettime64  = cpts_ptp_gettime,
-   .settime64  = cpts_ptp_settime,
-   .enable = cpts_ptp_enable,
-};
-
-static void cpts_overflow_check(struct kthread_work *work)
+static long cpts_overflow_check(struct ptp_clock_info *ptp)
 {
-   struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
+   struct cpts *cpts = container_of(ptp, struct cpts, info);
unsigned long delay = cpts->ov_check_period;
struct timespec64 ts;
unsigned long flags;
@@ -309,9 +295,24 @@ static void cpts_overflow_check(struct kthread_work *work)
spin_unlock_irqrestore(>lock, flags);
 
pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
-   kthread_queue_delayed_work(cpts->kworker, >overflow_work, delay);
+   return (long)delay;
 }
 
+static struct ptp_clock_info cpts_info = {
+   .owner  = THIS_MODULE,
+   .name   = "CTPS timer",
+   .max_adj= 100,
+   .n_ext_ts   = 0,
+   .n_pins = 0,
+   .pps= 0,
+   .adjfreq= cpts_ptp_adjfreq,
+   .adjtime= cpts_ptp_adjtime,
+   .gettime64  = cpts_ptp_gettime,
+   .settime64  = cpts_ptp_settime,
+   .enable = cpts_ptp_enable,
+   .do_aux_work= cpts_overflow_check,
+};
+
 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
  u16 ts_seqid, u8 ts_msgtype)
 {
@@ -392,8 +393,7 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff 
*skb, int ev_type)
/* get the timestamp for timeouts */
skb_cb->tmo = jiffies + msecs_to_jiffies(100);
__skb_queue_tail(>txq, skb);
-   kthread_mod_delayed_work(cpts->kworker,
->overflow_work, 0);
+   ptp_schedule_worker(cpts->clock, 0);
}
spin_unlock_irqrestore(>lock, flags);
 
@@ -457,8 +457,7 @@ int cpts_register(struct cpts *cpts)
}
cpts->phc_index = ptp_clock_index(cpts->clock);
 
-   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
-  cpts->ov_check_period);
+   ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
return 0;
 
 err_ptp:
@@ -472,8 +471,6 @@ void cpts_unregister(struct cpts *cpts)
if (WARN_ON(!cpts->clock))
return;
 
-   kthread_cancel_delayed_work_sync(>overflow_work);
-

Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-21 Thread Richard Cochran 
On Fri, Jul 21, 2017 at 06:49:42PM -0500, Grygorii Strashko wrote:
> There could be significant delay in CPTS work schedule under high system
> load and on -RT which could cause CPTS misbehavior due to internal counter
> overflow. Usage of own kthread_worker allows to avoid such kind of issues
> and makes it possible to tune priority of CPTS kthread_worker thread on -RT
> (thread name "cpts").

I have also seen excessive delays in the time stamp work from the
dp83640 under certain loads.  Can we please implement this time stamp
kthread_worker in the PHC subsystem?  That way, the facility can be
used by other drivers without code duplication.

Thanks,
Richard

Re: [PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-21 Thread Richard Cochran 
On Fri, Jul 21, 2017 at 06:49:42PM -0500, Grygorii Strashko wrote:
> There could be significant delay in CPTS work schedule under high system
> load and on -RT which could cause CPTS misbehavior due to internal counter
> overflow. Usage of own kthread_worker allows to avoid such kind of issues
> and makes it possible to tune priority of CPTS kthread_worker thread on -RT
> (thread name "cpts").

I have also seen excessive delays in the time stamp work from the
dp83640 under certain loads.  Can we please implement this time stamp
kthread_worker in the PHC subsystem?  That way, the facility can be
used by other drivers without code duplication.

Thanks,
Richard

[PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-21 Thread Grygorii Strashko 
There could be significant delay in CPTS work schedule under high system
load and on -RT which could cause CPTS misbehavior due to internal counter
overflow. Usage of own kthread_worker allows to avoid such kind of issues
and makes it possible to tune priority of CPTS kthread_worker thread on -RT
(thread name "cpts").

Signed-off-by: Grygorii Strashko 
---
 drivers/net/ethernet/ti/cpts.c | 23 +--
 drivers/net/ethernet/ti/cpts.h |  4 +++-
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 32279d2..6a520ae 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -20,12 +20,12 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
 #include 
 #include 
-#include 
 #include 
 #include 
 
@@ -238,14 +238,15 @@ static struct ptp_clock_info cpts_info = {
.enable = cpts_ptp_enable,
 };
 
-static void cpts_overflow_check(struct work_struct *work)
+static void cpts_overflow_check(struct kthread_work *work)
 {
struct timespec64 ts;
struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
 
cpts_ptp_gettime(>info, );
pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
-   schedule_delayed_work(>overflow_work, cpts->ov_check_period);
+   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
+  cpts->ov_check_period);
 }
 
 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
@@ -378,7 +379,8 @@ int cpts_register(struct cpts *cpts)
}
cpts->phc_index = ptp_clock_index(cpts->clock);
 
-   schedule_delayed_work(>overflow_work, cpts->ov_check_period);
+   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
+  cpts->ov_check_period);
return 0;
 
 err_ptp:
@@ -392,7 +394,7 @@ void cpts_unregister(struct cpts *cpts)
if (WARN_ON(!cpts->clock))
return;
 
-   cancel_delayed_work_sync(>overflow_work);
+   kthread_cancel_delayed_work_sync(>overflow_work);
 
ptp_clock_unregister(cpts->clock);
cpts->clock = NULL;
@@ -476,7 +478,6 @@ struct cpts *cpts_create(struct device *dev, void __iomem 
*regs,
cpts->dev = dev;
cpts->reg = (struct cpsw_cpts __iomem *)regs;
spin_lock_init(>lock);
-   INIT_DELAYED_WORK(>overflow_work, cpts_overflow_check);
 
ret = cpts_of_parse(cpts, node);
if (ret)
@@ -488,6 +489,14 @@ struct cpts *cpts_create(struct device *dev, void __iomem 
*regs,
return ERR_PTR(PTR_ERR(cpts->refclk));
}
 
+   kthread_init_delayed_work(>overflow_work, cpts_overflow_check);
+   cpts->kworker = kthread_create_worker(0, "cpts");
+   if (IS_ERR(cpts->kworker)) {
+   dev_err(dev, "failed to create cpts overflow_work task %ld\n",
+   PTR_ERR(cpts->kworker));
+   return ERR_CAST(cpts->kworker);
+   }
+
clk_prepare(cpts->refclk);
 
cpts->cc.read = cpts_systim_read;
@@ -513,6 +522,8 @@ void cpts_release(struct cpts *cpts)
return;
 
clk_unprepare(cpts->refclk);
+
+   kthread_destroy_worker(cpts->kworker);
 }
 EXPORT_SYMBOL_GPL(cpts_release);
 
diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h
index 01ea82b..e8128e8 100644
--- a/drivers/net/ethernet/ti/cpts.h
+++ b/drivers/net/ethernet/ti/cpts.h
@@ -27,6 +27,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -119,13 +120,14 @@ struct cpts {
u32 cc_mult; /* for the nominal frequency */
struct cyclecounter cc;
struct timecounter tc;
-   struct delayed_work overflow_work;
int phc_index;
struct clk *refclk;
struct list_head events;
struct list_head pool;
struct cpts_event pool_data[CPTS_MAX_EVENTS];
unsigned long ov_check_period;
+   struct kthread_worker *kworker;
+   struct kthread_delayed_work overflow_work;
 };
 
 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb);
-- 
2.10.1

[PATCH 1/2] net: ethernet: ti: cpts: convert to use kthread_worker

2017-07-21 Thread Grygorii Strashko 
There could be significant delay in CPTS work schedule under high system
load and on -RT which could cause CPTS misbehavior due to internal counter
overflow. Usage of own kthread_worker allows to avoid such kind of issues
and makes it possible to tune priority of CPTS kthread_worker thread on -RT
(thread name "cpts").

Signed-off-by: Grygorii Strashko 
---
 drivers/net/ethernet/ti/cpts.c | 23 +--
 drivers/net/ethernet/ti/cpts.h |  4 +++-
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 32279d2..6a520ae 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -20,12 +20,12 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
 #include 
 #include 
-#include 
 #include 
 #include 
 
@@ -238,14 +238,15 @@ static struct ptp_clock_info cpts_info = {
.enable = cpts_ptp_enable,
 };
 
-static void cpts_overflow_check(struct work_struct *work)
+static void cpts_overflow_check(struct kthread_work *work)
 {
struct timespec64 ts;
struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
 
cpts_ptp_gettime(>info, );
pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
-   schedule_delayed_work(>overflow_work, cpts->ov_check_period);
+   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
+  cpts->ov_check_period);
 }
 
 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
@@ -378,7 +379,8 @@ int cpts_register(struct cpts *cpts)
}
cpts->phc_index = ptp_clock_index(cpts->clock);
 
-   schedule_delayed_work(>overflow_work, cpts->ov_check_period);
+   kthread_queue_delayed_work(cpts->kworker, >overflow_work,
+  cpts->ov_check_period);
return 0;
 
 err_ptp:
@@ -392,7 +394,7 @@ void cpts_unregister(struct cpts *cpts)
if (WARN_ON(!cpts->clock))
return;
 
-   cancel_delayed_work_sync(>overflow_work);
+   kthread_cancel_delayed_work_sync(>overflow_work);
 
ptp_clock_unregister(cpts->clock);
cpts->clock = NULL;
@@ -476,7 +478,6 @@ struct cpts *cpts_create(struct device *dev, void __iomem 
*regs,
cpts->dev = dev;
cpts->reg = (struct cpsw_cpts __iomem *)regs;
spin_lock_init(>lock);
-   INIT_DELAYED_WORK(>overflow_work, cpts_overflow_check);
 
ret = cpts_of_parse(cpts, node);
if (ret)
@@ -488,6 +489,14 @@ struct cpts *cpts_create(struct device *dev, void __iomem 
*regs,
return ERR_PTR(PTR_ERR(cpts->refclk));
}
 
+   kthread_init_delayed_work(>overflow_work, cpts_overflow_check);
+   cpts->kworker = kthread_create_worker(0, "cpts");
+   if (IS_ERR(cpts->kworker)) {
+   dev_err(dev, "failed to create cpts overflow_work task %ld\n",
+   PTR_ERR(cpts->kworker));
+   return ERR_CAST(cpts->kworker);
+   }
+
clk_prepare(cpts->refclk);
 
cpts->cc.read = cpts_systim_read;
@@ -513,6 +522,8 @@ void cpts_release(struct cpts *cpts)
return;
 
clk_unprepare(cpts->refclk);
+
+   kthread_destroy_worker(cpts->kworker);
 }
 EXPORT_SYMBOL_GPL(cpts_release);
 
diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h
index 01ea82b..e8128e8 100644
--- a/drivers/net/ethernet/ti/cpts.h
+++ b/drivers/net/ethernet/ti/cpts.h
@@ -27,6 +27,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -119,13 +120,14 @@ struct cpts {
u32 cc_mult; /* for the nominal frequency */
struct cyclecounter cc;
struct timecounter tc;
-   struct delayed_work overflow_work;
int phc_index;
struct clk *refclk;
struct list_head events;
struct list_head pool;
struct cpts_event pool_data[CPTS_MAX_EVENTS];
unsigned long ov_check_period;
+   struct kthread_worker *kworker;
+   struct kthread_delayed_work overflow_work;
 };
 
 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb);
-- 
2.10.1