[RFC v6 20/23] clockevents: purge ->min_delta_ns

Nicolai Stange
2016-09-09T20:19:13Z

The struct clock_event_device's ->min_delta_ns member isn't used anymore.

Purge it.

In __clockevents_update_bounds(), shortcut the
->min_delta_ticks => ->min_delta_ns => ->min_delta_ticks_adjusted
calculation detour -- it had been made solely for the purpose of ensuring
that ->min_delta_ticks_adjusted corresponds to something >= 1us.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
include/linux/clockchips.h | 2 --
kernel/time/clockevents.c | 12 +++++-------
2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 7c3a193..2ff15f03 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -94,7 +94,6 @@ enum clock_event_state {
* @tick_resume: resume clkevt device
* @broadcast: function to broadcast events
* @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
- * @min_delta_ns: minimum delta value in ns
* @name: ptr to clock event name
* @rating: variable to rate clock event devices
* @irq: IRQ number (only for non CPU local devices)
@@ -127,7 +126,6 @@ struct clock_event_device {
void (*suspend)(struct clock_event_device *);
void (*resume)(struct clock_event_device *);
unsigned long min_delta_ticks;
- u64 min_delta_ns;

const char *name;
int rating;
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 86d9f97..394b8dc 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -492,14 +492,12 @@ static void __clockevents_update_bounds(struct clock_event_device *dev)
}

/*
- * cev_delta2ns() never returns values less than 1us and thus,
- * we'll never program any ced with anything less.
+ * Enforce ->min_delta_ticks_adjusted to correspond to a value
+ * >= 1us.
*/
- dev->min_delta_ns = cev_delta2ns(dev->min_delta_ticks, dev, false);
- dev->min_delta_ticks_adjusted = (unsigned long)((dev->min_delta_ns *
- dev->mult) >> dev->shift);
- dev->min_delta_ticks_adjusted = max(dev->min_delta_ticks_adjusted,
- dev->min_delta_ticks);
+ dev->min_delta_ticks_adjusted =
+ max(dev->min_delta_ticks,
+ (unsigned long)((1000ULL * dev->mult) >> dev->shift));
}

/**
--
2.9.3