[PATCH v2 0/3] Use helper clockevents_config_and_register()

[PATCH v2 0/3] Use helper clockevents_config_and_register()

[Shawn Guo]

The clockevent core is able to figure out the best mult and shift,
calculate min_delta_ns and max_delta_ns, with the necessary info passed
into clockevents_config_and_register().  Use this handy helper to make
the drivers less error prone and save some LOC.

Changes since v1:
 - Add one patch to export clockevents_config_and_register for fixing
   the error [1] reported by Fengguang.
 - Add Acked-by and Tested-by tags given by people (Thanks!)

[1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/209152

Shawn Guo (3):
  clockevents: export clockevents_config_and_register for module use
  ARM: use clockevents_config_and_register() where possible
  clocksource: use clockevents_config_and_register() where possible

 arch/arm/mach-at91/at91rm9200_time.c     |    7 ++-----
 arch/arm/mach-cns3xxx/core.c             |   13 +++----------
 arch/arm/mach-exynos/mct.c               |   18 ++++--------------
 arch/arm/mach-footbridge/dc21285-timer.c |    6 +-----
 arch/arm/mach-imx/epit.c                 |   15 +++------------
 arch/arm/mach-imx/time.c                 |   15 +++------------
 arch/arm/mach-ixp4xx/common.c            |   11 ++---------
 arch/arm/mach-lpc32xx/timer.c            |    9 +--------
 arch/arm/mach-mmp/time.c                 |    7 ++-----
 arch/arm/mach-msm/timer.c                |    6 +-----
 arch/arm/mach-mxs/timer.c                |   24 +++++-------------------
 arch/arm/mach-netx/time.c                |   10 ++--------
 arch/arm/mach-omap1/time.c               |   11 ++---------
 arch/arm/mach-omap1/timer32k.c           |   12 ++----------
 arch/arm/mach-omap2/timer.c              |   13 +++----------
 arch/arm/mach-prima2/timer.c             |   10 ++--------
 arch/arm/mach-pxa/time.c                 |    8 ++------
 arch/arm/mach-sa1100/time.c              |    8 ++------
 arch/arm/mach-tegra/timer.c              |    8 ++------
 arch/arm/mach-vt8500/timer.c             |    9 ++-------
 arch/arm/mach-w90x900/time.c             |   10 ++--------
 arch/arm/plat-iop/time.c                 |    9 ++-------
 arch/arm/plat-orion/time.c               |    6 +-----
 arch/arm/plat-samsung/s5p-time.c         |    9 +--------
 arch/arm/plat-spear/time.c               |    8 +-------
 drivers/clocksource/cs5535-clockevt.c    |   11 ++---------
 drivers/clocksource/sunxi_timer.c        |   11 ++---------
 drivers/clocksource/tcb_clksrc.c         |    7 +------
 kernel/time/clockevents.c                |    1 +
 29 files changed, 59 insertions(+), 233 deletions(-)

-- 
1.7.9.5

[PATCH v2 1/3] clockevents: export clockevents_config_and_register for module use

[Shawn Guo]

clockevents_config_and_register is a handy helper for clockevent
drivers, some of which might support module build, so export the symbol.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/time/clockevents.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 30b6de0..c6d6400 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -339,6 +339,7 @@ void clockevents_config_and_register(struct clock_event_device *dev,
 	clockevents_config(dev, freq);
 	clockevents_register_device(dev);
 }
+EXPORT_SYMBOL_GPL(clockevents_config_and_register);
 
 /**
  * clockevents_update_freq - Update frequency and reprogram a clock event device.
-- 
1.7.9.5

[PATCH v2 2/3] ARM: use clockevents_config_and_register() where possible

[Shawn Guo]

The clockevent core is able to figure out the best mult and shift,
calculate min_delta_ns and max_delta_ns, with the necessary info passed
into clockevents_config_and_register().  Use this combined configure
and register function where possible to make the codes less error prone
and gain some positive diff stat.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Barry Song <baohua.song@csr.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/mach-at91/at91rm9200_time.c     |    7 ++-----
 arch/arm/mach-cns3xxx/core.c             |   13 +++----------
 arch/arm/mach-exynos/mct.c               |   18 ++++--------------
 arch/arm/mach-footbridge/dc21285-timer.c |    6 +-----
 arch/arm/mach-imx/epit.c                 |   15 +++------------
 arch/arm/mach-imx/time.c                 |   15 +++------------
 arch/arm/mach-ixp4xx/common.c            |   11 ++---------
 arch/arm/mach-lpc32xx/timer.c            |    9 +--------
 arch/arm/mach-mmp/time.c                 |    7 ++-----
 arch/arm/mach-msm/timer.c                |    6 +-----
 arch/arm/mach-mxs/timer.c                |   24 +++++-------------------
 arch/arm/mach-netx/time.c                |   10 ++--------
 arch/arm/mach-omap1/time.c               |   11 ++---------
 arch/arm/mach-omap1/timer32k.c           |   12 ++----------
 arch/arm/mach-omap2/timer.c              |   13 +++----------
 arch/arm/mach-prima2/timer.c             |   10 ++--------
 arch/arm/mach-pxa/time.c                 |    8 ++------
 arch/arm/mach-sa1100/time.c              |    8 ++------
 arch/arm/mach-tegra/timer.c              |    8 ++------
 arch/arm/mach-vt8500/timer.c             |    9 ++-------
 arch/arm/mach-w90x900/time.c             |   10 ++--------
 arch/arm/plat-iop/time.c                 |    9 ++-------
 arch/arm/plat-orion/time.c               |    6 +-----
 arch/arm/plat-samsung/s5p-time.c         |    9 +--------
 arch/arm/plat-spear/time.c               |    8 +-------
 25 files changed, 53 insertions(+), 209 deletions(-)

diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index cafe988..20a28ac 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -174,7 +174,6 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
 static struct clock_event_device clkevt = {
 	.name		= "at91_tick",
 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.rating		= 150,
 	.set_next_event	= clkevt32k_next_event,
 	.set_mode	= clkevt32k_mode,
@@ -265,11 +264,9 @@ void __init at91rm9200_timer_init(void)
 	at91_st_write(AT91_ST_RTMR, 1);
 
 	/* Setup timer clockevent, with minimum of two ticks (important!!) */
-	clkevt.mult = div_sc(AT91_SLOW_CLOCK, NSEC_PER_SEC, clkevt.shift);
-	clkevt.max_delta_ns = clockevent_delta2ns(AT91_ST_ALMV, &clkevt);
-	clkevt.min_delta_ns = clockevent_delta2ns(2, &clkevt) + 1;
 	clkevt.cpumask = cpumask_of(0);
-	clockevents_register_device(&clkevt);
+	clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK,
+					2, AT91_ST_ALMV);
 
 	/* register clocksource */
 	clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);
diff --git a/arch/arm/mach-cns3xxx/core.c b/arch/arm/mach-cns3xxx/core.c
index 031805b..3eb74d1 100644
--- a/arch/arm/mach-cns3xxx/core.c
+++ b/arch/arm/mach-cns3xxx/core.c
@@ -134,7 +134,6 @@ static int cns3xxx_timer_set_next_event(unsigned long evt,
 
 static struct clock_event_device cns3xxx_tmr1_clockevent = {
 	.name		= "cns3xxx timer1",
-	.shift		= 8,
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.set_mode	= cns3xxx_timer_set_mode,
 	.set_next_event	= cns3xxx_timer_set_next_event,
@@ -145,15 +144,9 @@ static struct clock_event_device cns3xxx_tmr1_clockevent = {
 static void __init cns3xxx_clockevents_init(unsigned int timer_irq)
 {
 	cns3xxx_tmr1_clockevent.irq = timer_irq;
-	cns3xxx_tmr1_clockevent.mult =
-		div_sc((cns3xxx_cpu_clock() >> 3) * 1000000, NSEC_PER_SEC,
-		       cns3xxx_tmr1_clockevent.shift);
-	cns3xxx_tmr1_clockevent.max_delta_ns =
-		clockevent_delta2ns(0xffffffff, &cns3xxx_tmr1_clockevent);
-	cns3xxx_tmr1_clockevent.min_delta_ns =
-		clockevent_delta2ns(0xf, &cns3xxx_tmr1_clockevent);
-
-	clockevents_register_device(&cns3xxx_tmr1_clockevent);
+	clockevents_config_and_register(&cns3xxx_tmr1_clockevent,
+					(cns3xxx_cpu_clock() >> 3) * 1000000,
+					0xf, 0xffffffff);
 }
 
 /*
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c
index 57668eb..070d51e 100644
--- a/arch/arm/mach-exynos/mct.c
+++ b/arch/arm/mach-exynos/mct.c
@@ -255,13 +255,9 @@ static struct irqaction mct_comp_event_irq = {
 
 static void exynos4_clockevent_init(void)
 {
-	clockevents_calc_mult_shift(&mct_comp_device, clk_rate, 5);
-	mct_comp_device.max_delta_ns =
-		clockevent_delta2ns(0xffffffff, &mct_comp_device);
-	mct_comp_device.min_delta_ns =
-		clockevent_delta2ns(0xf, &mct_comp_device);
 	mct_comp_device.cpumask = cpumask_of(0);
-	clockevents_register_device(&mct_comp_device);
+	clockevents_config_and_register(&mct_comp_device, clk_rate,
+					0xf, 0xffffffff);
 
 	if (soc_is_exynos5250())
 		setup_irq(EXYNOS5_IRQ_MCT_G0, &mct_comp_event_irq);
@@ -404,14 +400,8 @@ static int __cpuinit exynos4_local_timer_setup(struct clock_event_device *evt)
 	evt->set_mode = exynos4_tick_set_mode;
 	evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 	evt->rating = 450;
-
-	clockevents_calc_mult_shift(evt, clk_rate / (TICK_BASE_CNT + 1), 5);
-	evt->max_delta_ns =
-		clockevent_delta2ns(0x7fffffff, evt);
-	evt->min_delta_ns =
-		clockevent_delta2ns(0xf, evt);
-
-	clockevents_register_device(evt);
+	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
+					0xf, 0x7fffffff);
 
 	exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
 
diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c
index 3b54196..a9918b6 100644
--- a/arch/arm/mach-footbridge/dc21285-timer.c
+++ b/arch/arm/mach-footbridge/dc21285-timer.c
@@ -101,12 +101,8 @@ static void __init footbridge_timer_init(void)
 
 	setup_irq(ce->irq, &footbridge_timer_irq);
 
-	clockevents_calc_mult_shift(ce, mem_fclk_21285, 5);
-	ce->max_delta_ns = clockevent_delta2ns(0xffffff, ce);
-	ce->min_delta_ns = clockevent_delta2ns(0x000004, ce);
 	ce->cpumask = cpumask_of(smp_processor_id());
-
-	clockevents_register_device(ce);
+	clockevents_config_and_register(ce, mem_fclk_21285, 0x4, 0xffffff);
 }
 
 struct sys_timer footbridge_timer = {
diff --git a/arch/arm/mach-imx/epit.c b/arch/arm/mach-imx/epit.c
index 04a5961..e02de18 100644
--- a/arch/arm/mach-imx/epit.c
+++ b/arch/arm/mach-imx/epit.c
@@ -178,7 +178,6 @@ static struct irqaction epit_timer_irq = {
 static struct clock_event_device clockevent_epit = {
 	.name		= "epit",
 	.features	= CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.set_mode	= epit_set_mode,
 	.set_next_event	= epit_set_next_event,
 	.rating		= 200,
@@ -186,18 +185,10 @@ static struct clock_event_device clockevent_epit = {
 
 static int __init epit_clockevent_init(struct clk *timer_clk)
 {
-	unsigned int c = clk_get_rate(timer_clk);
-
-	clockevent_epit.mult = div_sc(c, NSEC_PER_SEC,
-					clockevent_epit.shift);
-	clockevent_epit.max_delta_ns =
-			clockevent_delta2ns(0xfffffffe, &clockevent_epit);
-	clockevent_epit.min_delta_ns =
-			clockevent_delta2ns(0x800, &clockevent_epit);
-
 	clockevent_epit.cpumask = cpumask_of(0);
-
-	clockevents_register_device(&clockevent_epit);
+	clockevents_config_and_register(&clockevent_epit,
+					clk_get_rate(timer_clk),
+					0x800, 0xfffffffe);
 
 	return 0;
 }
diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c
index f017302..62769df 100644
--- a/arch/arm/mach-imx/time.c
+++ b/arch/arm/mach-imx/time.c
@@ -256,7 +256,6 @@ static struct irqaction mxc_timer_irq = {
 static struct clock_event_device clockevent_mxc = {
 	.name		= "mxc_timer1",
 	.features	= CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.set_mode	= mxc_set_mode,
 	.set_next_event	= mx1_2_set_next_event,
 	.rating		= 200,
@@ -264,21 +263,13 @@ static struct clock_event_device clockevent_mxc = {
 
 static int __init mxc_clockevent_init(struct clk *timer_clk)
 {
-	unsigned int c = clk_get_rate(timer_clk);
-
 	if (timer_is_v2())
 		clockevent_mxc.set_next_event = v2_set_next_event;
 
-	clockevent_mxc.mult = div_sc(c, NSEC_PER_SEC,
-					clockevent_mxc.shift);
-	clockevent_mxc.max_delta_ns =
-			clockevent_delta2ns(0xfffffffe, &clockevent_mxc);
-	clockevent_mxc.min_delta_ns =
-			clockevent_delta2ns(0xff, &clockevent_mxc);
-
 	clockevent_mxc.cpumask = cpumask_of(0);
-
-	clockevents_register_device(&clockevent_mxc);
+	clockevents_config_and_register(&clockevent_mxc,
+					clk_get_rate(timer_clk),
+					0xff, 0xfffffffe);
 
 	return 0;
 }
diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 8c0c0e2..65ff98c 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -523,22 +523,15 @@ static struct clock_event_device clockevent_ixp4xx = {
 	.name		= "ixp4xx timer1",
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.rating         = 200,
-	.shift		= 24,
 	.set_mode	= ixp4xx_set_mode,
 	.set_next_event	= ixp4xx_set_next_event,
 };
 
 static void __init ixp4xx_clockevent_init(void)
 {
-	clockevent_ixp4xx.mult = div_sc(IXP4XX_TIMER_FREQ, NSEC_PER_SEC,
-					clockevent_ixp4xx.shift);
-	clockevent_ixp4xx.max_delta_ns =
-		clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
-	clockevent_ixp4xx.min_delta_ns =
-		clockevent_delta2ns(0xf, &clockevent_ixp4xx);
 	clockevent_ixp4xx.cpumask = cpumask_of(0);
-
-	clockevents_register_device(&clockevent_ixp4xx);
+	clockevents_config_and_register(&clockevent_ixp4xx, IXP4XX_TIMER_FREQ,
+					0xf, 0xfffffffe);
 }
 
 void ixp4xx_restart(char mode, const char *cmd)
diff --git a/arch/arm/mach-lpc32xx/timer.c b/arch/arm/mach-lpc32xx/timer.c
index c40667c..502b3c6 100644
--- a/arch/arm/mach-lpc32xx/timer.c
+++ b/arch/arm/mach-lpc32xx/timer.c
@@ -70,7 +70,6 @@ static void lpc32xx_clkevt_mode(enum clock_event_mode mode,
 static struct clock_event_device lpc32xx_clkevt = {
 	.name		= "lpc32xx_clkevt",
 	.features	= CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.rating		= 300,
 	.set_next_event	= lpc32xx_clkevt_next_event,
 	.set_mode	= lpc32xx_clkevt_mode,
@@ -141,14 +140,8 @@ static void __init lpc32xx_timer_init(void)
 	setup_irq(IRQ_LPC32XX_TIMER0, &lpc32xx_timer_irq);
 
 	/* Setup the clockevent structure. */
-	lpc32xx_clkevt.mult = div_sc(clkrate, NSEC_PER_SEC,
-		lpc32xx_clkevt.shift);
-	lpc32xx_clkevt.max_delta_ns = clockevent_delta2ns(-1,
-		&lpc32xx_clkevt);
-	lpc32xx_clkevt.min_delta_ns = clockevent_delta2ns(1,
-		&lpc32xx_clkevt) + 1;
 	lpc32xx_clkevt.cpumask = cpumask_of(0);
-	clockevents_register_device(&lpc32xx_clkevt);
+	clockevents_config_and_register(&lpc32xx_clkevt, clkrate, 1, -1);
 
 	/* Use timer1 as clock source. */
 	__raw_writel(LPC32XX_TIMER_CNTR_TCR_RESET,
diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
index 936447c..86a18b3 100644
--- a/arch/arm/mach-mmp/time.c
+++ b/arch/arm/mach-mmp/time.c
@@ -141,7 +141,6 @@ static void timer_set_mode(enum clock_event_mode mode,
 static struct clock_event_device ckevt = {
 	.name		= "clockevent",
 	.features	= CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.rating		= 200,
 	.set_next_event	= timer_set_next_event,
 	.set_mode	= timer_set_mode,
@@ -198,15 +197,13 @@ void __init timer_init(int irq)
 
 	setup_sched_clock(mmp_read_sched_clock, 32, CLOCK_TICK_RATE);
 
-	ckevt.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt.shift);
-	ckevt.max_delta_ns = clockevent_delta2ns(MAX_DELTA, &ckevt);
-	ckevt.min_delta_ns = clockevent_delta2ns(MIN_DELTA, &ckevt);
 	ckevt.cpumask = cpumask_of(0);
 
 	setup_irq(irq, &timer_irq);
 
 	clocksource_register_hz(&cksrc, CLOCK_TICK_RATE);
-	clockevents_register_device(&ckevt);
+	clockevents_config_and_register(&ckevt, CLOCK_TICK_RATE,
+					MIN_DELTA, MAX_DELTA);
 }
 
 #ifdef CONFIG_OF
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 476549a..b9e7449 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -144,13 +144,9 @@ static int __cpuinit msm_local_timer_setup(struct clock_event_device *evt)
 	evt->rating = msm_clockevent.rating;
 	evt->set_mode = msm_timer_set_mode;
 	evt->set_next_event = msm_timer_set_next_event;
-	evt->shift = msm_clockevent.shift;
-	evt->mult = div_sc(GPT_HZ, NSEC_PER_SEC, evt->shift);
-	evt->max_delta_ns = clockevent_delta2ns(0xf0000000, evt);
-	evt->min_delta_ns = clockevent_delta2ns(4, evt);
 
 	*__this_cpu_ptr(msm_evt.percpu_evt) = evt;
-	clockevents_register_device(evt);
+	clockevents_config_and_register(evt, GPT_HZ, 4, 0xf0000000);
 	enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
 	return 0;
 }
diff --git a/arch/arm/mach-mxs/timer.c b/arch/arm/mach-mxs/timer.c
index 856f4c7..27451b1 100644
--- a/arch/arm/mach-mxs/timer.c
+++ b/arch/arm/mach-mxs/timer.c
@@ -195,7 +195,6 @@ static void mxs_set_mode(enum clock_event_mode mode,
 static struct clock_event_device mxs_clockevent_device = {
 	.name		= "mxs_timrot",
 	.features	= CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.set_mode	= mxs_set_mode,
 	.set_next_event	= timrotv2_set_next_event,
 	.rating		= 200,
@@ -203,25 +202,12 @@ static struct clock_event_device mxs_clockevent_device = {
 
 static int __init mxs_clockevent_init(struct clk *timer_clk)
 {
-	unsigned int c = clk_get_rate(timer_clk);
-
-	mxs_clockevent_device.mult =
-		div_sc(c, NSEC_PER_SEC, mxs_clockevent_device.shift);
-	mxs_clockevent_device.cpumask = cpumask_of(0);
-	if (timrot_is_v1()) {
+	if (timrot_is_v1())
 		mxs_clockevent_device.set_next_event = timrotv1_set_next_event;
-		mxs_clockevent_device.max_delta_ns =
-			clockevent_delta2ns(0xfffe, &mxs_clockevent_device);
-		mxs_clockevent_device.min_delta_ns =
-			clockevent_delta2ns(0xf, &mxs_clockevent_device);
-	} else {
-		mxs_clockevent_device.max_delta_ns =
-			clockevent_delta2ns(0xfffffffe, &mxs_clockevent_device);
-		mxs_clockevent_device.min_delta_ns =
-			clockevent_delta2ns(0xf, &mxs_clockevent_device);
-	}
-
-	clockevents_register_device(&mxs_clockevent_device);
+	mxs_clockevent_device.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&mxs_clockevent_device,
+					clk_get_rate(timer_clk), 0xf,
+					timrot_is_v1() ? 0xfffe : 0xfffffffe);
 
 	return 0;
 }
diff --git a/arch/arm/mach-netx/time.c b/arch/arm/mach-netx/time.c
index e24c141..d780a93 100644
--- a/arch/arm/mach-netx/time.c
+++ b/arch/arm/mach-netx/time.c
@@ -76,7 +76,6 @@ static int netx_set_next_event(unsigned long evt,
 
 static struct clock_event_device netx_clockevent = {
 	.name = "netx-timer" __stringify(TIMER_CLOCKEVENT),
-	.shift = 32,
 	.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.set_next_event = netx_set_next_event,
 	.set_mode = netx_set_mode,
@@ -140,16 +139,11 @@ static void __init netx_timer_init(void)
 	clocksource_mmio_init(NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE),
 		"netx_timer", CLOCK_TICK_RATE, 200, 32, clocksource_mmio_readl_up);
 
-	netx_clockevent.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC,
-			netx_clockevent.shift);
-	netx_clockevent.max_delta_ns =
-		clockevent_delta2ns(0xfffffffe, &netx_clockevent);
 	/* with max_delta_ns >= delta2ns(0x800) the system currently runs fine.
 	 * Adding some safety ... */
-	netx_clockevent.min_delta_ns =
-		clockevent_delta2ns(0xa00, &netx_clockevent);
 	netx_clockevent.cpumask = cpumask_of(0);
-	clockevents_register_device(&netx_clockevent);
+	clockevents_config_and_register(&netx_clockevent, CLOCK_TICK_RATE,
+					0xa00, 0xfffffffe);
 }
 
 struct sys_timer netx_timer = {
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index 4d4816f..5b7c556 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -145,7 +145,6 @@ static void omap_mpu_set_mode(enum clock_event_mode mode,
 static struct clock_event_device clockevent_mpu_timer1 = {
 	.name		= "mpu_timer1",
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.set_next_event	= omap_mpu_set_next_event,
 	.set_mode	= omap_mpu_set_mode,
 };
@@ -170,15 +169,9 @@ static __init void omap_init_mpu_timer(unsigned long rate)
 	setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
 	omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
 
-	clockevent_mpu_timer1.mult = div_sc(rate, NSEC_PER_SEC,
-					    clockevent_mpu_timer1.shift);
-	clockevent_mpu_timer1.max_delta_ns =
-		clockevent_delta2ns(-1, &clockevent_mpu_timer1);
-	clockevent_mpu_timer1.min_delta_ns =
-		clockevent_delta2ns(1, &clockevent_mpu_timer1);
-
 	clockevent_mpu_timer1.cpumask = cpumask_of(0);
-	clockevents_register_device(&clockevent_mpu_timer1);
+	clockevents_config_and_register(&clockevent_mpu_timer1, rate,
+					1, -1);
 }
 
 
diff --git a/arch/arm/mach-omap1/timer32k.c b/arch/arm/mach-omap1/timer32k.c
index 41152fa..0b74246 100644
--- a/arch/arm/mach-omap1/timer32k.c
+++ b/arch/arm/mach-omap1/timer32k.c
@@ -140,7 +140,6 @@ static void omap_32k_timer_set_mode(enum clock_event_mode mode,
 static struct clock_event_device clockevent_32k_timer = {
 	.name		= "32k-timer",
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.set_next_event	= omap_32k_timer_set_next_event,
 	.set_mode	= omap_32k_timer_set_mode,
 };
@@ -165,16 +164,9 @@ static __init void omap_init_32k_timer(void)
 {
 	setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
 
-	clockevent_32k_timer.mult = div_sc(OMAP_32K_TICKS_PER_SEC,
-					   NSEC_PER_SEC,
-					   clockevent_32k_timer.shift);
-	clockevent_32k_timer.max_delta_ns =
-		clockevent_delta2ns(0xfffffffe, &clockevent_32k_timer);
-	clockevent_32k_timer.min_delta_ns =
-		clockevent_delta2ns(1, &clockevent_32k_timer);
-
 	clockevent_32k_timer.cpumask = cpumask_of(0);
-	clockevents_register_device(&clockevent_32k_timer);
+	clockevents_config_and_register(&clockevent_32k_timer,
+					OMAP_32K_TICKS_PER_SEC, 1, 0xfffffffe);
 }
 
 /*
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 691aa67..3e2ffdb 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -131,7 +131,6 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
 static struct clock_event_device clockevent_gpt = {
 	.name		= "gp_timer",
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.rating		= 300,
 	.set_next_event	= omap2_gp_timer_set_next_event,
 	.set_mode	= omap2_gp_timer_set_mode,
@@ -340,17 +339,11 @@ static void __init omap2_gp_clockevent_init(int gptimer_id,
 
 	__omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
 
-	clockevent_gpt.mult = div_sc(clkev.rate, NSEC_PER_SEC,
-				     clockevent_gpt.shift);
-	clockevent_gpt.max_delta_ns =
-		clockevent_delta2ns(0xffffffff, &clockevent_gpt);
-	clockevent_gpt.min_delta_ns =
-		clockevent_delta2ns(3, &clockevent_gpt);
-		/* Timer internal resynch latency. */
-
 	clockevent_gpt.cpumask = cpu_possible_mask;
 	clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
-	clockevents_register_device(&clockevent_gpt);
+	clockevents_config_and_register(&clockevent_gpt, clkev.rate,
+					3, /* Timer internal resynch latency */
+					0xffffffff);
 
 	pr_info("OMAP clockevent source: GPTIMER%d at %lu Hz\n",
 		gptimer_id, clkev.rate);
diff --git a/arch/arm/mach-prima2/timer.c b/arch/arm/mach-prima2/timer.c
index d95bf25..4f69e67 100644
--- a/arch/arm/mach-prima2/timer.c
+++ b/arch/arm/mach-prima2/timer.c
@@ -175,15 +175,9 @@ static u32 notrace sirfsoc_read_sched_clock(void)
 
 static void __init sirfsoc_clockevent_init(void)
 {
-	clockevents_calc_mult_shift(&sirfsoc_clockevent, CLOCK_TICK_RATE, 60);
-
-	sirfsoc_clockevent.max_delta_ns =
-		clockevent_delta2ns(-2, &sirfsoc_clockevent);
-	sirfsoc_clockevent.min_delta_ns =
-		clockevent_delta2ns(2, &sirfsoc_clockevent);
-
 	sirfsoc_clockevent.cpumask = cpumask_of(0);
-	clockevents_register_device(&sirfsoc_clockevent);
+	clockevents_config_and_register(&sirfsoc_clockevent, CLOCK_TICK_RATE,
+					2, -2);
 }
 
 /* initialize the kernel jiffy timer source */
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index 4bc47d6..08cc47f 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -113,18 +113,14 @@ static void __init pxa_timer_init(void)
 
 	setup_sched_clock(pxa_read_sched_clock, 32, clock_tick_rate);
 
-	clockevents_calc_mult_shift(&ckevt_pxa_osmr0, clock_tick_rate, 4);
-	ckevt_pxa_osmr0.max_delta_ns =
-		clockevent_delta2ns(0x7fffffff, &ckevt_pxa_osmr0);
-	ckevt_pxa_osmr0.min_delta_ns =
-		clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_pxa_osmr0) + 1;
 	ckevt_pxa_osmr0.cpumask = cpumask_of(0);
 
 	setup_irq(IRQ_OST0, &pxa_ost0_irq);
 
 	clocksource_mmio_init(OSCR, "oscr0", clock_tick_rate, 200, 32,
 		clocksource_mmio_readl_up);
-	clockevents_register_device(&ckevt_pxa_osmr0);
+	clockevents_config_and_register(&ckevt_pxa_osmr0, clock_tick_rate,
+					MIN_OSCR_DELTA * 2, 0x7fffffff);
 }
 
 #ifdef CONFIG_PM
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index 80702c9..6e980da 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -91,18 +91,14 @@ static void __init sa1100_timer_init(void)
 
 	setup_sched_clock(sa1100_read_sched_clock, 32, 3686400);
 
-	clockevents_calc_mult_shift(&ckevt_sa1100_osmr0, 3686400, 4);
-	ckevt_sa1100_osmr0.max_delta_ns =
-		clockevent_delta2ns(0x7fffffff, &ckevt_sa1100_osmr0);
-	ckevt_sa1100_osmr0.min_delta_ns =
-		clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_sa1100_osmr0) + 1;
 	ckevt_sa1100_osmr0.cpumask = cpumask_of(0);
 
 	setup_irq(IRQ_OST0, &sa1100_timer_irq);
 
 	clocksource_mmio_init(OSCR, "oscr", CLOCK_TICK_RATE, 200, 32,
 		clocksource_mmio_readl_up);
-	clockevents_register_device(&ckevt_sa1100_osmr0);
+	clockevents_config_and_register(&ckevt_sa1100_osmr0, 3686400,
+					MIN_OSCR_DELTA * 2, 0x7fffffff);
 }
 
 #ifdef CONFIG_PM
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
index e4863f3..bc86161 100644
--- a/arch/arm/mach-tegra/timer.c
+++ b/arch/arm/mach-tegra/timer.c
@@ -259,14 +259,10 @@ static void __init tegra_init_timer(void)
 		BUG();
 	}
 
-	clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5);
-	tegra_clockevent.max_delta_ns =
-		clockevent_delta2ns(0x1fffffff, &tegra_clockevent);
-	tegra_clockevent.min_delta_ns =
-		clockevent_delta2ns(0x1, &tegra_clockevent);
 	tegra_clockevent.cpumask = cpu_all_mask;
 	tegra_clockevent.irq = tegra_timer_irq.irq;
-	clockevents_register_device(&tegra_clockevent);
+	clockevents_config_and_register(&tegra_clockevent, 1000000,
+					0x1, 0x1fffffff);
 #ifdef CONFIG_HAVE_ARM_TWD
 	twd_local_timer_of_register();
 #endif
diff --git a/arch/arm/mach-vt8500/timer.c b/arch/arm/mach-vt8500/timer.c
index 3dd21a4..ed66cf0 100644
--- a/arch/arm/mach-vt8500/timer.c
+++ b/arch/arm/mach-vt8500/timer.c
@@ -168,17 +168,12 @@ void __init vt8500_timer_init(void)
 		pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
 					__func__, clocksource.name);
 
-	clockevents_calc_mult_shift(&clockevent, VT8500_TIMER_HZ, 4);
-
-	/* copy-pasted from mach-msm; no idea */
-	clockevent.max_delta_ns =
-		clockevent_delta2ns(0xf0000000, &clockevent);
-	clockevent.min_delta_ns = clockevent_delta2ns(4, &clockevent);
 	clockevent.cpumask = cpumask_of(0);
 
 	if (setup_irq(timer_irq, &irq))
 		pr_err("%s: setup_irq failed for %s\n", __func__,
 							clockevent.name);
-	clockevents_register_device(&clockevent);
+	clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ,
+					4, 0xf0000000);
 }
 
diff --git a/arch/arm/mach-w90x900/time.c b/arch/arm/mach-w90x900/time.c
index fa27c49..b61ab3e 100644
--- a/arch/arm/mach-w90x900/time.c
+++ b/arch/arm/mach-w90x900/time.c
@@ -91,7 +91,6 @@ static int nuc900_clockevent_setnextevent(unsigned long evt,
 
 static struct clock_event_device nuc900_clockevent_device = {
 	.name		= "nuc900-timer0",
-	.shift		= 32,
 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.set_mode	= nuc900_clockevent_setmode,
 	.set_next_event	= nuc900_clockevent_setnextevent,
@@ -133,15 +132,10 @@ static void __init nuc900_clockevents_init(void)
 	__raw_writel(RESETINT, REG_TISR);
 	setup_irq(IRQ_TIMER0, &nuc900_timer0_irq);
 
-	nuc900_clockevent_device.mult = div_sc(rate, NSEC_PER_SEC,
-					nuc900_clockevent_device.shift);
-	nuc900_clockevent_device.max_delta_ns = clockevent_delta2ns(0xffffffff,
-					&nuc900_clockevent_device);
-	nuc900_clockevent_device.min_delta_ns = clockevent_delta2ns(0xf,
-					&nuc900_clockevent_device);
 	nuc900_clockevent_device.cpumask = cpumask_of(0);
 
-	clockevents_register_device(&nuc900_clockevent_device);
+	clockevents_config_and_register(&nuc900_clockevent_device, rate,
+					0xf, 0xffffffff);
 }
 
 static void __init nuc900_clocksource_init(void)
diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c
index cbfbbe4..837a2d5 100644
--- a/arch/arm/plat-iop/time.c
+++ b/arch/arm/plat-iop/time.c
@@ -156,14 +156,9 @@ void __init iop_init_time(unsigned long tick_rate)
 	write_tmr0(timer_ctl & ~IOP_TMR_EN);
 	write_tisr(1);
 	setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
-	clockevents_calc_mult_shift(&iop_clockevent,
-				    tick_rate, IOP_MIN_RANGE);
-	iop_clockevent.max_delta_ns =
-		clockevent_delta2ns(0xfffffffe, &iop_clockevent);
-	iop_clockevent.min_delta_ns =
-		clockevent_delta2ns(0xf, &iop_clockevent);
 	iop_clockevent.cpumask = cpumask_of(0);
-	clockevents_register_device(&iop_clockevent);
+	clockevents_config_and_register(&iop_clockevent, tick_rate,
+					0xf, 0xfffffffe);
 
 	/*
 	 * Set up free-running clocksource timer 1.
diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
index 0f4fa86..5d5ac0f 100644
--- a/arch/arm/plat-orion/time.c
+++ b/arch/arm/plat-orion/time.c
@@ -156,7 +156,6 @@ orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
 static struct clock_event_device orion_clkevt = {
 	.name		= "orion_tick",
 	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
-	.shift		= 32,
 	.rating		= 300,
 	.set_next_event	= orion_clkevt_next_event,
 	.set_mode	= orion_clkevt_mode,
@@ -221,9 +220,6 @@ orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
 	 * Setup clockevent timer (interrupt-driven).
 	 */
 	setup_irq(irq, &orion_timer_irq);
-	orion_clkevt.mult = div_sc(tclk, NSEC_PER_SEC, orion_clkevt.shift);
-	orion_clkevt.max_delta_ns = clockevent_delta2ns(0xfffffffe, &orion_clkevt);
-	orion_clkevt.min_delta_ns = clockevent_delta2ns(1, &orion_clkevt);
 	orion_clkevt.cpumask = cpumask_of(0);
-	clockevents_register_device(&orion_clkevt);
+	clockevents_config_and_register(&orion_clkevt, tclk, 1, 0xfffffffe);
 }
diff --git a/arch/arm/plat-samsung/s5p-time.c b/arch/arm/plat-samsung/s5p-time.c
index 028b6e8..798268b 100644
--- a/arch/arm/plat-samsung/s5p-time.c
+++ b/arch/arm/plat-samsung/s5p-time.c
@@ -274,15 +274,8 @@ static void __init s5p_clockevent_init(void)
 	clock_rate = clk_get_rate(tin_event);
 	clock_count_per_tick = clock_rate / HZ;
 
-	clockevents_calc_mult_shift(&time_event_device,
-				    clock_rate, S5PTIMER_MIN_RANGE);
-	time_event_device.max_delta_ns =
-		clockevent_delta2ns(-1, &time_event_device);
-	time_event_device.min_delta_ns =
-		clockevent_delta2ns(1, &time_event_device);
-
 	time_event_device.cpumask = cpumask_of(0);
-	clockevents_register_device(&time_event_device);
+	clockevents_config_and_register(&time_event_device, clock_rate, 1, -1);
 
 	irq_number = timer_source.event_id + IRQ_TIMER0;
 	setup_irq(irq_number, &s5p_clock_event_irq);
diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
index 03321af..bd5c53c 100644
--- a/arch/arm/plat-spear/time.c
+++ b/arch/arm/plat-spear/time.c
@@ -186,15 +186,9 @@ static void __init spear_clockevent_init(int irq)
 	tick_rate = clk_get_rate(gpt_clk);
 	tick_rate >>= CTRL_PRESCALER16;
 
-	clockevents_calc_mult_shift(&clkevt, tick_rate, SPEAR_MIN_RANGE);
-
-	clkevt.max_delta_ns = clockevent_delta2ns(0xfff0,
-			&clkevt);
-	clkevt.min_delta_ns = clockevent_delta2ns(3, &clkevt);
-
 	clkevt.cpumask = cpumask_of(0);
 
-	clockevents_register_device(&clkevt);
+	clockevents_config_and_register(&clkevt, tick_rate, 3, 0xfff0);
 
 	setup_irq(irq, &spear_timer_irq);
 }
-- 
1.7.9.5

[PATCH v2 3/3] clocksource: use clockevents_config_and_register() where possible

[Shawn Guo]

The clockevent core is able to figure out the best mult and shift,
calculate min_delta_ns and max_delta_ns, with the necessary info passed
into clockevents_config_and_register().  Use this combined configure
and register function where possible to make the codes less error prone
and gain some positive diff stat.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clocksource/cs5535-clockevt.c |   11 ++---------
 drivers/clocksource/sunxi_timer.c     |   11 ++---------
 drivers/clocksource/tcb_clksrc.c      |    7 +------
 3 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
index d927938..ea21048 100644
--- a/drivers/clocksource/cs5535-clockevt.c
+++ b/drivers/clocksource/cs5535-clockevt.c
@@ -100,7 +100,6 @@ static struct clock_event_device cs5535_clockevent = {
 	.set_mode = mfgpt_set_mode,
 	.set_next_event = mfgpt_next_event,
 	.rating = 250,
-	.shift = 32
 };
 
 static irqreturn_t mfgpt_tick(int irq, void *dev_id)
@@ -169,17 +168,11 @@ static int __init cs5535_mfgpt_init(void)
 	cs5535_mfgpt_write(cs5535_event_clock, MFGPT_REG_SETUP, val);
 
 	/* Set up the clock event */
-	cs5535_clockevent.mult = div_sc(MFGPT_HZ, NSEC_PER_SEC,
-			cs5535_clockevent.shift);
-	cs5535_clockevent.min_delta_ns = clockevent_delta2ns(0xF,
-			&cs5535_clockevent);
-	cs5535_clockevent.max_delta_ns = clockevent_delta2ns(0xFFFE,
-			&cs5535_clockevent);
-
 	printk(KERN_INFO DRV_NAME
 		": Registering MFGPT timer as a clock event, using IRQ %d\n",
 		timer_irq);
-	clockevents_register_device(&cs5535_clockevent);
+	clockevents_config_and_register(&cs5535_clockevent, MFGPT_HZ,
+					0xF, 0xFFFE);
 
 	return 0;
 
diff --git a/drivers/clocksource/sunxi_timer.c b/drivers/clocksource/sunxi_timer.c
index 3cd1bd3..f911866 100644
--- a/drivers/clocksource/sunxi_timer.c
+++ b/drivers/clocksource/sunxi_timer.c
@@ -74,7 +74,6 @@ static int sunxi_clkevt_next_event(unsigned long evt,
 
 static struct clock_event_device sunxi_clockevent = {
 	.name = "sunxi_tick",
-	.shift = 32,
 	.rating = 300,
 	.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.set_mode = sunxi_clkevt_mode,
@@ -154,16 +153,10 @@ static void __init sunxi_timer_init(void)
 	val = readl(timer_base + TIMER_CTL_REG);
 	writel(val | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG);
 
-	sunxi_clockevent.mult = div_sc(rate / TIMER_SCAL,
-				NSEC_PER_SEC,
-				sunxi_clockevent.shift);
-	sunxi_clockevent.max_delta_ns = clockevent_delta2ns(0xff,
-							    &sunxi_clockevent);
-	sunxi_clockevent.min_delta_ns = clockevent_delta2ns(0x1,
-							    &sunxi_clockevent);
 	sunxi_clockevent.cpumask = cpumask_of(0);
 
-	clockevents_register_device(&sunxi_clockevent);
+	clockevents_config_and_register(&sunxi_clockevent, rate / TIMER_SCAL,
+					0x1, 0xff);
 }
 
 struct sys_timer sunxi_timer = {
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 32cb929..8a61872 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -157,7 +157,6 @@ static struct tc_clkevt_device clkevt = {
 		.name		= "tc_clkevt",
 		.features	= CLOCK_EVT_FEAT_PERIODIC
 					| CLOCK_EVT_FEAT_ONESHOT,
-		.shift		= 32,
 		/* Should be lower than at91rm9200's system timer */
 		.rating		= 125,
 		.set_next_event	= tc_next_event,
@@ -196,13 +195,9 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
 	timer_clock = clk32k_divisor_idx;
 
-	clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
-	clkevt.clkevt.max_delta_ns
-		= clockevent_delta2ns(0xffff, &clkevt.clkevt);
-	clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
-	clockevents_register_device(&clkevt.clkevt);
+	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
 
 	setup_irq(irq, &tc_irqaction);
 }
-- 
1.7.9.5

Re: [PATCH v2 0/3] Use helper clockevents_config_and_register()

[Arnd Bergmann]

On Saturday 12 January 2013, Shawn Guo wrote:
> The clockevent core is able to figure out the best mult and shift,
> calculate min_delta_ns and max_delta_ns, with the necessary info passed
> into clockevents_config_and_register().  Use this handy helper to make
> the drivers less error prone and save some LOC.
> 
> Changes since v1:
>  - Add one patch to export clockevents_config_and_register for fixing
>    the error [1] reported by Fengguang.
>  - Add Acked-by and Tested-by tags given by people (Thanks!)
> 
> [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/209152

Very nice series!

Acked-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH v2 2/3] ARM: use clockevents_config_and_register() where possible

[Jason Cooper]

On Sat, Jan 12, 2013 at 07:50:05PM +0800, Shawn Guo wrote:
> The clockevent core is able to figure out the best mult and shift,
> calculate min_delta_ns and max_delta_ns, with the necessary info passed
> into clockevents_config_and_register().  Use this combined configure
> and register function where possible to make the codes less error prone
> and gain some positive diff stat.
> 
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com>
> Acked-by: Kukjin Kim <kgene.kim@samsung.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Tested-by: Roland Stigge <stigge@antcom.de>
> Acked-by: Eric Miao <eric.y.miao@gmail.com>
> Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
> Cc: David Brown <davidb@codeaurora.org>
> Tested-by: Tony Lindgren <tony@atomide.com>
> Acked-by: Barry Song <baohua.song@csr.com>
> Tested-by: Stephen Warren <swarren@nvidia.com>
> Acked-by: Tony Prisk <linux@prisktech.co.nz>
> Cc: Lennert Buytenhek <buytenh@wantstofly.org>
> Cc: Wan ZongShun <mcuos.com@gmail.com>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> ---
...
>  arch/arm/plat-orion/time.c               |    6 +-----
...

Acked-by: Jason Cooper <jason@lakedaemon.net>

thx,

Jason.

Re: [PATCH v2 0/3] Use helper clockevents_config_and_register()

[Thomas Gleixner]

On Sat, 12 Jan 2013, Arnd Bergmann wrote:
> On Saturday 12 January 2013, Shawn Guo wrote:
> > The clockevent core is able to figure out the best mult and shift,
> > calculate min_delta_ns and max_delta_ns, with the necessary info passed
> > into clockevents_config_and_register().  Use this handy helper to make
> > the drivers less error prone and save some LOC.
> > 
> > Changes since v1:
> >  - Add one patch to export clockevents_config_and_register for fixing
> >    the error [1] reported by Fengguang.
> >  - Add Acked-by and Tested-by tags given by people (Thanks!)
> > 
> > [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/209152
> 
> Very nice series!
> 
> Acked-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Arnd, can you take the whole lot via the ARM tree? The export should
not cause any conflicts, and if it does Linus should be able to solve
it :)

Thanks,

	tglx

 

Re: [PATCH v2 0/3] Use helper clockevents_config_and_register()

[Olof Johansson]

On Mon, Jan 14, 2013 at 12:23:16PM +0100, Thomas Gleixner wrote:
> On Sat, 12 Jan 2013, Arnd Bergmann wrote:
> > On Saturday 12 January 2013, Shawn Guo wrote:
> > > The clockevent core is able to figure out the best mult and shift,
> > > calculate min_delta_ns and max_delta_ns, with the necessary info passed
> > > into clockevents_config_and_register().  Use this handy helper to make
> > > the drivers less error prone and save some LOC.
> > > 
> > > Changes since v1:
> > >  - Add one patch to export clockevents_config_and_register for fixing
> > >    the error [1] reported by Fengguang.
> > >  - Add Acked-by and Tested-by tags given by people (Thanks!)
> > > 
> > > [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/209152
> > 
> > Very nice series!
> > 
> > Acked-by: Arnd Bergmann <arnd@arndb.de>
> 
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> 
> Arnd, can you take the whole lot via the ARM tree? The export should
> not cause any conflicts, and if it does Linus should be able to solve
> it :)

(with the presumed s/Arnd/Arnd or Olof/)

Great! I've applied these to a clockevent/cleanup topic branch in arm-soc,
together with the added acks, etc.


-Olof

BUG: Re: [PATCH v2 3/3] clocksource: use clockevents_config_and_register() where possible

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 2538 bytes --]

Hello,

On 01/12/2013 12:50 PM, Shawn Guo wrote:
> The clockevent core is able to figure out the best mult and shift,
> calculate min_delta_ns and max_delta_ns, with the necessary info passed
> into clockevents_config_and_register().  Use this combined configure
> and register function where possible to make the codes less error prone
> and gain some positive diff stat.
> 
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> Cc: Andres Salomon <dilinger@queued.net>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

[...]

I just bisected a timer problem down to this commit.

> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 32cb929..8a61872 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -157,7 +157,6 @@ static struct tc_clkevt_device clkevt = {
>  		.name		= "tc_clkevt",
>  		.features	= CLOCK_EVT_FEAT_PERIODIC
>  					| CLOCK_EVT_FEAT_ONESHOT,
> -		.shift		= 32,
>  		/* Should be lower than at91rm9200's system timer */
>  		.rating		= 125,
>  		.set_next_event	= tc_next_event,
> @@ -196,13 +195,9 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>  
>  	timer_clock = clk32k_divisor_idx;
>  
> -	clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
> -	clkevt.clkevt.max_delta_ns
> -		= clockevent_delta2ns(0xffff, &clkevt.clkevt);
> -	clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
                                                                           ^^^^^^

With this patch, the "+ 1" gets lost, resulting in a different
"min_delta_ns".

good:
setup_clkevents: shift=32 mult=140737 min=30518 max=1999976422

bad:
setup_clkevents: shift=32 mult=140737 min=30517 max=1999976422

This leads to problems with schedule_delayed_work() with a delay of
"1". These worksqueues seem to be hanging for several seconds. I'll
send a RFC patch.

>  	clkevt.clkevt.cpumask = cpumask_of(0);
>  
> -	clockevents_register_device(&clkevt.clkevt);
> +	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
>  
>  	setup_irq(irq, &tc_irqaction);
>  }
> 

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
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RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

The commit

    77cc982 clocksource: use clockevents_config_and_register() where possible

switches from manually calculating min_delta_ns (and others) and
clockevents_register_device() to automatic calculation via
clockevents_config_and_register(). During this conversation the "+ 1" in

    min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;

was lost. This leads to problems with schedule_delayed_work() with a delay of
"1". Resulting in the work not scheduled in time.

This patch fixes the problem by increasing the min_delta to "2" ticks.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/clocksource/tcb_clksrc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..7cf6dc7 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
-	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
 
 	setup_irq(irq, &tc_irqaction);
 }
-- 
1.8.2.rc2

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 1134 bytes --]

On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote:
> The commit
> 
>     77cc982 clocksource: use clockevents_config_and_register() where possible
> 
> switches from manually calculating min_delta_ns (and others) and
> clockevents_register_device() to automatic calculation via
> clockevents_config_and_register(). During this conversation the "+ 1" in
> 
>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> 
> was lost. This leads to problems with schedule_delayed_work() with a delay of
> "1". Resulting in the work not scheduled in time.
> 
> This patch fixes the problem by increasing the min_delta to "2" ticks.
> 
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The problem appears on at91sam9263. This patch successfully fixes the
problem and applies to current linus/master (post v3.9-rc8).

regards,
Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Shawn Guo]

On Tue, Apr 23, 2013 at 03:11:33PM +0200, Marc Kleine-Budde wrote:
> On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote:
> > The commit
> > 
> >     77cc982 clocksource: use clockevents_config_and_register() where possible
> > 
> > switches from manually calculating min_delta_ns (and others) and
> > clockevents_register_device() to automatic calculation via
> > clockevents_config_and_register(). During this conversation the "+ 1" in
> > 
> >     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> > 
> > was lost. This leads to problems with schedule_delayed_work() with a delay of
> > "1". Resulting in the work not scheduled in time.
> > 
> > This patch fixes the problem by increasing the min_delta to "2" ticks.
> > 
> > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> 
> The problem appears on at91sam9263. This patch successfully fixes the
> problem and applies to current linus/master (post v3.9-rc8).

Thanks for the fixing, Marc.

Acked-by: Shawn Guo <shawn.guo@linaro.org>

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 2313 bytes --]

On 04/23/2013 03:44 PM, Shawn Guo wrote:
> On Tue, Apr 23, 2013 at 03:11:33PM +0200, Marc Kleine-Budde wrote:
>> On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote:
>>> The commit
>>>
>>>     77cc982 clocksource: use clockevents_config_and_register() where possible
>>>
>>> switches from manually calculating min_delta_ns (and others) and
>>> clockevents_register_device() to automatic calculation via
>>> clockevents_config_and_register(). During this conversation the "+ 1" in
>>>
>>>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
>>>
>>> was lost. This leads to problems with schedule_delayed_work() with a delay of
>>> "1". Resulting in the work not scheduled in time.
>>>
>>> This patch fixes the problem by increasing the min_delta to "2" ticks.
>>>
>>> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
>>
>> The problem appears on at91sam9263. This patch successfully fixes the
>> problem and applies to current linus/master (post v3.9-rc8).
> 
> Thanks for the fixing, Marc.
> 
> Acked-by: Shawn Guo <shawn.guo@linaro.org>

Thanks. The downside of my RFC Patch is, that min_delta_ns is increased
from 30518 to 61035:

good: setup_clkevents: shift=32 mult=140737 min=30518 max=1999976422
bad:  setup_clkevents: shift=32 mult=140737 min=30517 max=1999976422
RFC:  setup_clkevents: shift=32 mult=140737 min=61035 max=1999976422

To keep the original min_delta_ns value of 30518, a rather hackish
option would be this:

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..30e0a68 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -198,6 +198,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
        clkevt.clkevt.cpumask = cpumask_of(0);

        clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+       clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;

        setup_irq(irq, &tc_irqaction);
 }

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
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Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 1690 bytes --]

On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote:
> The commit
> 
>     77cc982 clocksource: use clockevents_config_and_register() where possible
> 
> switches from manually calculating min_delta_ns (and others) and
> clockevents_register_device() to automatic calculation via
> clockevents_config_and_register(). During this conversation the "+ 1" in
> 
>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> 
> was lost. This leads to problems with schedule_delayed_work() with a delay of
> "1". Resulting in the work not scheduled in time.
> 
> This patch fixes the problem by increasing the min_delta to "2" ticks.
> 
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Who will take care of this patch?

Marc

> ---
>  drivers/clocksource/tcb_clksrc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 8a61872..7cf6dc7 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>  
>  	clkevt.clkevt.cpumask = cpumask_of(0);
>  
> -	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
> +	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
>  
>  	setup_irq(irq, &tc_irqaction);
>  }
> 


-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 263 bytes --]

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Thomas Gleixner]

On Thu, 25 Apr 2013, Marc Kleine-Budde wrote:

> On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote:
> > The commit
> > 
> >     77cc982 clocksource: use clockevents_config_and_register() where possible
> > 
> > switches from manually calculating min_delta_ns (and others) and
> > clockevents_register_device() to automatic calculation via
> > clockevents_config_and_register(). During this conversation the "+ 1" in
> > 
> >     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> > 
> > was lost. This leads to problems with schedule_delayed_work() with a delay of
> > "1". Resulting in the work not scheduled in time.
> > 
> > This patch fixes the problem by increasing the min_delta to "2" ticks.
> > 
> > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> 
> Who will take care of this patch?

If you had cc'ed me in the first place ...
 
> Marc
> 
> > ---
> >  drivers/clocksource/tcb_clksrc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> > index 8a61872..7cf6dc7 100644
> > --- a/drivers/clocksource/tcb_clksrc.c
> > +++ b/drivers/clocksource/tcb_clksrc.c
> > @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
> >  
> >  	clkevt.clkevt.cpumask = cpumask_of(0);
> >  
> > -	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
> > +	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
> >  
> >  	setup_irq(irq, &tc_irqaction);
> >  }
> > 
> 
> 
> -- 
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
> 
> 

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Thomas Gleixner]

On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
> The commit
> 
>     77cc982 clocksource: use clockevents_config_and_register() where possible
> 
> switches from manually calculating min_delta_ns (and others) and
> clockevents_register_device() to automatic calculation via
> clockevents_config_and_register(). During this conversation the "+ 1" in
> 
>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> 
> was lost. This leads to problems with schedule_delayed_work() with a delay of
> "1". Resulting in the work not scheduled in time.

Errm. How is schedule_delayed_work() related to this?

schedule_delayed_work() is jiffies based and has absolutely nothing to
do with clockevents.
 
> This patch fixes the problem by increasing the min_delta to "2" ticks.

This changelog sucks.

> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/clocksource/tcb_clksrc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 8a61872..7cf6dc7 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>  
>  	clkevt.clkevt.cpumask = cpumask_of(0);
>  
> -	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
> +	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
>  
>  	setup_irq(irq, &tc_irqaction);
>  }
> -- 
> 1.8.2.rc2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

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On 04/25/2013 04:21 PM, Thomas Gleixner wrote:
> On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
>> The commit
>>
>>     77cc982 clocksource: use clockevents_config_and_register() where possible
>>
>> switches from manually calculating min_delta_ns (and others) and
>> clockevents_register_device() to automatic calculation via
>> clockevents_config_and_register(). During this conversation the "+ 1" in
>>
>>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
>>
>> was lost. This leads to problems with schedule_delayed_work() with a delay of
>> "1". Resulting in the work not scheduled in time.
> 
> Errm. How is schedule_delayed_work() related to this?

Let me explain:
For other reasons [1], we reverted:

    f23eb2b tty: stop using "delayed_work" in the tty layer

(for reference find the patch below [2]). Which basically means
tty_schedule_flip() uses schedule_delayed_work(&buf->work, 1) instead
of schedule_work(&buf->work) as mainline does.

This works pretty well until v3.8. With v3.9-rc kernel the serial
console gets sluggish. It takes several seconds to abort a "find /" on
a serial console with Ctrl+c. I've bisected the problem down to:

    77cc982 clocksource: use clockevents_config_and_register() where
            possible

A printk shows the subtile difference in the min_delta_ns:

good: setup_clkevents: shift=32 mult=140737 min=30518 max=1999976422
bad:  setup_clkevents: shift=32 mult=140737 min=30517 max=1999976422

Restoring min_delta_ns to the original value, with this hackish patch,
"fixes" the serial problem, too:

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..30e0a68 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -198,6 +198,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
        clkevt.clkevt.cpumask = cpumask_of(0);

        clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+       clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;

        setup_irq(irq, &tc_irqaction);
 }

> schedule_delayed_work() is jiffies based and has absolutely nothing to
> do with clockevents.

I'm puzzled, too.

>> This patch fixes the problem by increasing the min_delta to "2" ticks.
> 
> This changelog sucks.
> 
>> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
>> ---
>>  drivers/clocksource/tcb_clksrc.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
>> index 8a61872..7cf6dc7 100644
>> --- a/drivers/clocksource/tcb_clksrc.c
>> +++ b/drivers/clocksource/tcb_clksrc.c
>> @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>>  
>>  	clkevt.clkevt.cpumask = cpumask_of(0);
>>  
>> -	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
>> +	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
>>  
>>  	setup_irq(irq, &tc_irqaction);
>>  }

[1] http://permalink.gmane.org/gmane.linux.kernel/1479280

[2]
From e4d43afca06724c6a59b8caac1f5dc07a9974aaa Mon Sep 17 00:00:00 2001
From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Date: Fri, 5 Apr 2013 16:38:55 +0200
Subject: [PATCH] HACK: tty: Revert stop using "delayed_work" in the tty layer

This patch reverts:

    f23eb2b tty: stop using "delayed_work" in the tty layer

That patch changed the tty buffer flip from beeing handled in a "delayed_work"
to an immediately scheduled "work". The original motivation was to decrease the
latency, this however leads to 15-25 %-points of more load on certain
workloads.

Here, less load is more desired than low latency, thus the patch is reverted
until a mainline accepted solution is found.

See for a detailed discussion see:
http://permalink.gmane.org/gmane.linux.kernel/1479280

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/tty/n_tty.c      |  2 +-
 drivers/tty/tty_buffer.c | 12 ++++++------
 drivers/tty/tty_ldisc.c  | 10 +++++-----
 include/linux/tty.h      |  2 +-
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 05e72be..ead46da 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -153,7 +153,7 @@ static void n_tty_set_room(struct tty_struct *tty)
 	if (left && !old_left) {
 		WARN_RATELIMIT(tty->port->itty == NULL,
 				"scheduling with invalid itty\n");
-		schedule_work(&tty->port->buf.work);
+		schedule_delayed_work(&tty->port->buf.work, 1);
 	}
 }
 
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 578aa75..187b874 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -339,7 +339,7 @@ void tty_schedule_flip(struct tty_port *port)
 	if (buf->tail != NULL)
 		buf->tail->commit = buf->tail->used;
 	spin_unlock_irqrestore(&buf->lock, flags);
-	schedule_work(&buf->work);
+	schedule_delayed_work(&buf->work, 1);
 }
 EXPORT_SYMBOL(tty_schedule_flip);
 
@@ -418,7 +418,7 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
 
 static void flush_to_ldisc(struct work_struct *work)
 {
-	struct tty_port *port = container_of(work, struct tty_port, buf.work);
+	struct tty_port *port = container_of(work, struct tty_port, buf.work.work);
 	struct tty_bufhead *buf = &port->buf;
 	struct tty_struct *tty;
 	unsigned long 	flags;
@@ -492,7 +492,7 @@ static void flush_to_ldisc(struct work_struct *work)
 void tty_flush_to_ldisc(struct tty_struct *tty)
 {
 	if (!tty->port->low_latency)
-		flush_work(&tty->port->buf.work);
+		flush_delayed_work(&tty->port->buf.work);
 }
 
 /**
@@ -520,9 +520,9 @@ void tty_flip_buffer_push(struct tty_port *port)
 	spin_unlock_irqrestore(&buf->lock, flags);
 
 	if (port->low_latency)
-		flush_to_ldisc(&buf->work);
+		flush_to_ldisc(&buf->work.work);
 	else
-		schedule_work(&buf->work);
+		schedule_delayed_work(&port->buf.work, 1);
 }
 EXPORT_SYMBOL(tty_flip_buffer_push);
 
@@ -545,6 +545,6 @@ void tty_buffer_init(struct tty_port *port)
 	buf->tail = NULL;
 	buf->free = NULL;
 	buf->memory_used = 0;
-	INIT_WORK(&buf->work, flush_to_ldisc);
+	INIT_DELAYED_WORK(&port->buf.work, flush_to_ldisc);
 }
 
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index d794087..1cb63f1 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -514,7 +514,7 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
 static int tty_ldisc_halt(struct tty_struct *tty)
 {
 	clear_bit(TTY_LDISC, &tty->flags);
-	return cancel_work_sync(&tty->port->buf.work);
+	return cancel_delayed_work(&tty->port->buf.work);
 }
 
 /**
@@ -527,7 +527,7 @@ static void tty_ldisc_flush_works(struct tty_struct *tty)
 {
 	flush_work(&tty->hangup_work);
 	flush_work(&tty->SAK_work);
-	flush_work(&tty->port->buf.work);
+	flush_delayed_work(&tty->port->buf.work);
 }
 
 /**
@@ -706,9 +706,9 @@ enable:
 	/* Restart the work queue in case no characters kick it off. Safe if
 	   already running */
 	if (work)
-		schedule_work(&tty->port->buf.work);
+		schedule_delayed_work(&tty->port->buf.work, 1);
 	if (o_work)
-		schedule_work(&o_tty->port->buf.work);
+		schedule_delayed_work(&o_tty->port->buf.work, 1);
 	mutex_unlock(&tty->ldisc_mutex);
 	tty_unlock(tty);
 	return retval;
@@ -819,7 +819,7 @@ void tty_ldisc_hangup(struct tty_struct *tty)
 	 */
 	clear_bit(TTY_LDISC, &tty->flags);
 	tty_unlock(tty);
-	cancel_work_sync(&tty->port->buf.work);
+	cancel_delayed_work(&tty->port->buf.work);
 	mutex_unlock(&tty->ldisc_mutex);
 retry:
 	tty_lock(tty);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index c75d886..f7f6836 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -52,7 +52,7 @@ struct tty_buffer {
 
 
 struct tty_bufhead {
-	struct work_struct work;
+	struct delayed_work work;
 	spinlock_t lock;
 	struct tty_buffer *head;	/* Queue head */
 	struct tty_buffer *tail;	/* Active buffer */
-- 
1.8.2.rc2

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

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Hello Thomas,

On 04/25/2013 04:53 PM, Marc Kleine-Budde wrote:
> On 04/25/2013 04:21 PM, Thomas Gleixner wrote:
>> On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
>>> The commit
>>>
>>>     77cc982 clocksource: use clockevents_config_and_register() where possible
>>>
>>> switches from manually calculating min_delta_ns (and others) and
>>> clockevents_register_device() to automatic calculation via
>>> clockevents_config_and_register(). During this conversation the "+ 1" in
>>>
>>>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
>>>
>>> was lost. This leads to problems with schedule_delayed_work() with a delay of
>>> "1". Resulting in the work not scheduled in time.
>>
>> Errm. How is schedule_delayed_work() related to this?

Coming back to the this problem after some time.

I'm on at91sam9263 (armv5) using latest linus/master (v3.10-rc6-84-gc069114).
I can illustrate the problem running cyclictest.

Here's the output of unpatched linus/master:

> root@halo22:~ cyclictest -i 10000 -n -t 4
> policy: other/other: loadavg: 0.10 0.19 0.10 2/31 133
> 
> T: 0 (  130) P: 0 I:10000 C:  30767 Min:     57 Act:  165 Avg:909453 Max: 201897444
> T: 1 (  131) P: 0 I:10500 C:  29302 Min:     68 Act:  144 Avg:906651 Max: 204005666
> T: 2 (  132) P: 0 I:11000 C:  27970 Min:     79 Act:  188 Avg:905068 Max: 204008666
> T: 3 (  133) P: 0 I:11500 C:  26754 Min:     52 Act:  132 Avg:904438 Max: 203665111

Cyclictest runs for about two seconds, but then shows no output for
about two seconds, then it runs again, then stops and so on...

With my patch applied, the numbers are back to normal:

> root@halo22:~ cyclictest -i 10000 -n -t 4
> policy: other/other: loadavg: 0.34 0.15 0.06 2/32 109
> 
> T: 0 (  106) P: 0 I:10000 C:    292 Min:    112 Act:  208 Avg:  189 Max:    1715
> T: 1 (  107) P: 0 I:10500 C:    277 Min:    107 Act:  198 Avg:  201 Max:    1464
> T: 2 (  108) P: 0 I:11000 C:    265 Min:    104 Act:  148 Avg:  195 Max:    1530
> T: 3 (  109) P: 0 I:11500 C:    252 Min:    113 Act:  205 Avg:  167 Max:     269

Cyclictest keeps running without 2 second stops.

Is my patch a valid solution to the problem? If so, I'll write more 
specific commit message.

regards,
Marc

---

The commit

    77cc982 clocksource: use clockevents_config_and_register() where possible

switches from manually calculating min_delta_ns (and others) and
clockevents_register_device() to automatic calculation via
clockevents_config_and_register(). During this conversation the "+ 1" in

    min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;

was lost. This leads to problems with schedule_delayed_work() with a delay of
"1". Resulting in the work not scheduled in time.

This patch fixes the problem by increasing the min_delta to "2" ticks.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/clocksource/tcb_clksrc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..7cf6dc7 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
-	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
 
 	setup_irq(irq, &tc_irqaction);
 }
-- 1.8.2.rc2

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Ronald Wahl]

On 20.06.2013 17:00, Marc Kleine-Budde wrote:
> Hello Thomas,
>
> On 04/25/2013 04:53 PM, Marc Kleine-Budde wrote:
>> On 04/25/2013 04:21 PM, Thomas Gleixner wrote:
>>> On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
>>>> The commit
>>>>
>>>>      77cc982 clocksource: use clockevents_config_and_register() where possible
>>>>
>>>> switches from manually calculating min_delta_ns (and others) and
>>>> clockevents_register_device() to automatic calculation via
>>>> clockevents_config_and_register(). During this conversation the "+ 1" in
>>>>
>>>>      min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
>>>>
>>>> was lost. This leads to problems with schedule_delayed_work() with a delay of
>>>> "1". Resulting in the work not scheduled in time.
>>>
>>> Errm. How is schedule_delayed_work() related to this?

I also stumbled over this issue now after upgrading from 3.4.57 to 
3.10.10. Even sleep() is unreliable - sleeping for 2 seconds often 
sleeps just more than 3 seconds.

The now lost +1 has actually been added in 2007 to solve a rounding issue:

   http://permalink.gmane.org/gmane.linux.kernel/549744

So I think this should either be fixed by always rounding up in 
clockevent_delta2ns() or by adding +1 to the min_delta_ns in the 
clockevents_config_and_register() function. Dunno if rounding up will 
cause problems with the max_delta_ns as it might be too big then so 
probably the second approach is better.

Opinions?

- ron

-- 
Ronald Wahl - ronald.wahl@raritan.com - Phone +49 375271349-0 Fax -99
Raritan Deutschland GmbH, Kornmarkt 7, 08056 Zwickau, Germany
USt-IdNr. DE813094160, Steuer-Nr. 227/117/01749
Amtsgericht Chemnitz HRB 23605
Geschäftsführung: Stuart Hopper, Ralf Ploenes

Re: RFC: [PATCH] clocksource: tcb: fix min_delta calculation

[Marc Kleine-Budde]

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On 09/09/2013 10:18 AM, Ronald Wahl wrote:
> On 20.06.2013 17:00, Marc Kleine-Budde wrote:
>> Hello Thomas,
>>
>> On 04/25/2013 04:53 PM, Marc Kleine-Budde wrote:
>>> On 04/25/2013 04:21 PM, Thomas Gleixner wrote:
>>>> On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
>>>>> The commit
>>>>>
>>>>>      77cc982 clocksource: use clockevents_config_and_register()
>>>>> where possible
>>>>>
>>>>> switches from manually calculating min_delta_ns (and others) and
>>>>> clockevents_register_device() to automatic calculation via
>>>>> clockevents_config_and_register(). During this conversation the "+
>>>>> 1" in
>>>>>
>>>>>      min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
>>>>>
>>>>> was lost. This leads to problems with schedule_delayed_work() with
>>>>> a delay of
>>>>> "1". Resulting in the work not scheduled in time.
>>>>
>>>> Errm. How is schedule_delayed_work() related to this?
> 
> I also stumbled over this issue now after upgrading from 3.4.57 to
> 3.10.10. Even sleep() is unreliable - sleeping for 2 seconds often
> sleeps just more than 3 seconds.
> 
> The now lost +1 has actually been added in 2007 to solve a rounding issue:
> 
>   http://permalink.gmane.org/gmane.linux.kernel/549744
> 
> So I think this should either be fixed by always rounding up in
> clockevent_delta2ns() or by adding +1 to the min_delta_ns in the
> clockevents_config_and_register() function. Dunno if rounding up will
> cause problems with the max_delta_ns as it might be too big then so
> probably the second approach is better.
> 
> Opinions?

Thomas, any thoughts on this?

Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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