[PATCH v4 2/3] net: ethernet: ti: cpts: convert to use ptp auxiliary worker

From: Grygorii Strashko
Date: Wed Jul 26 2017 - 18:12:28 EST


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.

Hence, the CPTS driver is converted to use PTP auxiliary worker as PHC
subsystem implements such functionality in a generic way now.

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/net/ethernet/ti/cpts.c | 27 +++++++++++++--------------
drivers/net/ethernet/ti/cpts.h | 1 -
2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 32279d2..3ed438e 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -224,6 +224,17 @@ static int cpts_ptp_enable(struct ptp_clock_info *ptp,
return -EOPNOTSUPP;
}

+static long cpts_overflow_check(struct ptp_clock_info *ptp)
+{
+ struct cpts *cpts = container_of(ptp, struct cpts, info);
+ unsigned long delay = cpts->ov_check_period;
+ struct timespec64 ts;
+
+ cpts_ptp_gettime(&cpts->info, &ts);
+ pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
+ return (long)delay;
+}
+
static struct ptp_clock_info cpts_info = {
.owner = THIS_MODULE,
.name = "CTPS timer",
@@ -236,18 +247,9 @@ static struct ptp_clock_info cpts_info = {
.gettime64 = cpts_ptp_gettime,
.settime64 = cpts_ptp_settime,
.enable = cpts_ptp_enable,
+ .do_aux_work = cpts_overflow_check,
};

-static void cpts_overflow_check(struct work_struct *work)
-{
- struct timespec64 ts;
- struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
-
- cpts_ptp_gettime(&cpts->info, &ts);
- pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
- schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period);
-}
-
static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
u16 ts_seqid, u8 ts_msgtype)
{
@@ -378,7 +380,7 @@ int cpts_register(struct cpts *cpts)
}
cpts->phc_index = ptp_clock_index(cpts->clock);

- schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period);
+ ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
return 0;

err_ptp:
@@ -392,8 +394,6 @@ void cpts_unregister(struct cpts *cpts)
if (WARN_ON(!cpts->clock))
return;

- cancel_delayed_work_sync(&cpts->overflow_work);
-
ptp_clock_unregister(cpts->clock);
cpts->clock = NULL;

@@ -476,7 +476,6 @@ struct cpts *cpts_create(struct device *dev, void __iomem *regs,
cpts->dev = dev;
cpts->reg = (struct cpsw_cpts __iomem *)regs;
spin_lock_init(&cpts->lock);
- INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);

ret = cpts_of_parse(cpts, node);
if (ret)
diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h
index 01ea82b..586edd9 100644
--- a/drivers/net/ethernet/ti/cpts.h
+++ b/drivers/net/ethernet/ti/cpts.h
@@ -119,7 +119,6 @@ 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;
--
2.10.1