| Message ID | 1380060159-12008-1-git-send-email-u.kleine-koenig@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
Hello, On Wed, Sep 25, 2013 at 12:02:39AM +0200, Uwe Kleine-König wrote: > clockevents_config_and_register is superior compared to setting > shift/mult and {min,max}_delta_ns by hand. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > Hello, > > I wonder where the 50 us limit comes from. This is not a hardware limit, > is it? ping; I didn't get any feedback on this yet, also it's not in next. Best regards Uwe > arch/arm/mach-davinci/time.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c > index 7a55b5c..627bf8b 100644 > --- a/arch/arm/mach-davinci/time.c > +++ b/arch/arm/mach-davinci/time.c > @@ -331,7 +331,6 @@ static void davinci_set_mode(enum clock_event_mode mode, > > static struct clock_event_device clockevent_davinci = { > .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, > - .shift = 32, > .set_next_event = davinci_set_next_event, > .set_mode = davinci_set_mode, > }; > @@ -397,14 +396,11 @@ void __init davinci_timer_init(void) > > /* setup clockevent */ > clockevent_davinci.name = id_to_name[timers[TID_CLOCKEVENT].id]; > - clockevent_davinci.mult = div_sc(davinci_clock_tick_rate, NSEC_PER_SEC, > - clockevent_davinci.shift); > - clockevent_davinci.max_delta_ns = > - clockevent_delta2ns(0xfffffffe, &clockevent_davinci); > - clockevent_davinci.min_delta_ns = 50000; /* 50 usec */ > > clockevent_davinci.cpumask = cpumask_of(0); > - clockevents_register_device(&clockevent_davinci); > + /* min tick corresponds to 50 usec assuming a 24 MHz clock */ > + clockevents_config_and_register(&clockevent_davinci, > + davinci_clock_tick_rate, 1200, 0xfffffffe); > > for (i=0; i< ARRAY_SIZE(timers); i++) > timer32_config(&timers[i]); > -- > 1.8.4.rc3 > >
Uwe, On Tuesday 08 October 2013 08:27 PM, Uwe Kleine-König wrote: > Hello, > > On Wed, Sep 25, 2013 at 12:02:39AM +0200, Uwe Kleine-König wrote: >> clockevents_config_and_register is superior compared to setting >> shift/mult and {min,max}_delta_ns by hand. >> >> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > >> --- >> Hello, >> >> I wonder where the 50 us limit comes from. This is not a hardware limit, >> is it? > ping; I didn't get any feedback on this yet, also it's not in next. Apologies for the delay. I am yet to look at it because I am traveling ATM. I will look at it during this week and provide feedback. Thanks, Sekhar
On Wednesday 25 September 2013 03:32 AM, Uwe Kleine-König wrote: > clockevents_config_and_register is superior compared to setting > shift/mult and {min,max}_delta_ns by hand. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > Hello, > > I wonder where the 50 us limit comes from. This is not a hardware limit, > is it? > > Best regards > Uwe > > arch/arm/mach-davinci/time.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c > index 7a55b5c..627bf8b 100644 > --- a/arch/arm/mach-davinci/time.c > +++ b/arch/arm/mach-davinci/time.c > @@ -331,7 +331,6 @@ static void davinci_set_mode(enum clock_event_mode mode, > > static struct clock_event_device clockevent_davinci = { > .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, > - .shift = 32, > .set_next_event = davinci_set_next_event, > .set_mode = davinci_set_mode, > }; > @@ -397,14 +396,11 @@ void __init davinci_timer_init(void) > > /* setup clockevent */ > clockevent_davinci.name = id_to_name[timers[TID_CLOCKEVENT].id]; > - clockevent_davinci.mult = div_sc(davinci_clock_tick_rate, NSEC_PER_SEC, > - clockevent_davinci.shift); > - clockevent_davinci.max_delta_ns = > - clockevent_delta2ns(0xfffffffe, &clockevent_davinci); > - clockevent_davinci.min_delta_ns = 50000; /* 50 usec */ > > clockevent_davinci.cpumask = cpumask_of(0); > - clockevents_register_device(&clockevent_davinci); > + /* min tick corresponds to 50 usec assuming a 24 MHz clock */ > + clockevents_config_and_register(&clockevent_davinci, > + davinci_clock_tick_rate, 1200, 0xfffffffe); Min ticks can be set to 1, IMO. I think the 50usec limit used earlier should have actually been 50ns assuming a 24MHz clock. Prabhakar, Can you please test this patch on a DaVinci platform you have with 1200 replaced with 1. I currently do not have access to a board. Thanks, Sekhar
Hi Sekhar, On 10/12/13, Sekhar Nori <nsekhar@ti.com> wrote: > On Wednesday 25 September 2013 03:32 AM, Uwe Kleine-König wrote: >> clockevents_config_and_register is superior compared to setting >> shift/mult and {min,max}_delta_ns by hand. [snip] >> >> + davinci_clock_tick_rate, 1200, 0xfffffffe); > > Min ticks can be set to 1, IMO. I think the 50usec limit used earlier > should have actually been 50ns assuming a 24MHz clock. > > Prabhakar, > > Can you please test this patch on a DaVinci platform you have with 1200 > replaced with 1. I currently do not have access to a board. > I have boot tested this patch on OMAP-L138 and tested the uptime (with min ticks set to 1), should that be enough ? Thanks, --Prabhakar Lad
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c index 7a55b5c..627bf8b 100644 --- a/arch/arm/mach-davinci/time.c +++ b/arch/arm/mach-davinci/time.c @@ -331,7 +331,6 @@ static void davinci_set_mode(enum clock_event_mode mode, static struct clock_event_device clockevent_davinci = { .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .shift = 32, .set_next_event = davinci_set_next_event, .set_mode = davinci_set_mode, }; @@ -397,14 +396,11 @@ void __init davinci_timer_init(void) /* setup clockevent */ clockevent_davinci.name = id_to_name[timers[TID_CLOCKEVENT].id]; - clockevent_davinci.mult = div_sc(davinci_clock_tick_rate, NSEC_PER_SEC, - clockevent_davinci.shift); - clockevent_davinci.max_delta_ns = - clockevent_delta2ns(0xfffffffe, &clockevent_davinci); - clockevent_davinci.min_delta_ns = 50000; /* 50 usec */ clockevent_davinci.cpumask = cpumask_of(0); - clockevents_register_device(&clockevent_davinci); + /* min tick corresponds to 50 usec assuming a 24 MHz clock */ + clockevents_config_and_register(&clockevent_davinci, + davinci_clock_tick_rate, 1200, 0xfffffffe); for (i=0; i< ARRAY_SIZE(timers); i++) timer32_config(&timers[i]);
clockevents_config_and_register is superior compared to setting shift/mult and {min,max}_delta_ns by hand. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- Hello, I wonder where the 50 us limit comes from. This is not a hardware limit, is it? Best regards Uwe arch/arm/mach-davinci/time.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)