| Message ID | 1352314890-22224-2-git-send-email-jon-hunter@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wednesday 07 November 2012 01:01 PM, Jon Hunter wrote: > For OMAP2+ devices, when using DMTIMERs for system timers (clock-events and > clock-source) the posted mode configuration of the timers is used. To allow > the compiler to optimise the functions for configuring and reading the system > timers, the posted flag variable is hard-coded with the value 1. To make it > clear that posted mode is being used add some definitions so that it is more > readable. > > Add separate definitions for the clock-events and clock-source timers so that > we can change the posted mode of clock-events and clock-source independently. > > Signed-off-by: Jon Hunter <jon-hunter@ti.com> > --- > arch/arm/mach-omap2/timer.c | 26 +++++++++++++++++++------- > arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++ > 2 files changed, 23 insertions(+), 7 deletions(-) > > diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c > index 0758bae..28c6078 100644 > --- a/arch/arm/mach-omap2/timer.c > +++ b/arch/arm/mach-omap2/timer.c > @@ -82,6 +82,13 @@ > #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14 > #define NUMERATOR_DENUMERATOR_MASK 0xfffff000 > > +/* > + * For clock-events timer, always use posted mode to > + * minimise CPU overhead for configuring the timer. > + */ > +#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED > +#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED > + I don't see need of above defines. Just use OMAP_TIMER_POSTED directly with API. Rest of the patch looks fine. Apart from above one comment, Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
On 11/07/2012 04:04 PM, Santosh Shilimkar wrote: > On Wednesday 07 November 2012 01:01 PM, Jon Hunter wrote: >> For OMAP2+ devices, when using DMTIMERs for system timers >> (clock-events and >> clock-source) the posted mode configuration of the timers is used. To >> allow >> the compiler to optimise the functions for configuring and reading the >> system >> timers, the posted flag variable is hard-coded with the value 1. To >> make it >> clear that posted mode is being used add some definitions so that it >> is more >> readable. >> >> Add separate definitions for the clock-events and clock-source timers >> so that >> we can change the posted mode of clock-events and clock-source >> independently. >> >> Signed-off-by: Jon Hunter <jon-hunter@ti.com> >> --- >> arch/arm/mach-omap2/timer.c | 26 >> +++++++++++++++++++------- >> arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++ >> 2 files changed, 23 insertions(+), 7 deletions(-) >> >> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >> index 0758bae..28c6078 100644 >> --- a/arch/arm/mach-omap2/timer.c >> +++ b/arch/arm/mach-omap2/timer.c >> @@ -82,6 +82,13 @@ >> #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14 >> #define NUMERATOR_DENUMERATOR_MASK 0xfffff000 >> >> +/* >> + * For clock-events timer, always use posted mode to >> + * minimise CPU overhead for configuring the timer. >> + */ >> +#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED >> +#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED >> + > I don't see need of above defines. Just use OMAP_TIMER_POSTED directly > with API. Rest of the patch looks fine. Yes that's possible, however, in patch #2, I am disabling posted mode for clock-source (see changelog of patch #2 for details). Having these #defines makes it easier to change the posted configuration. That was the real motivation here. Cheers Jon
On Wednesday 07 November 2012 04:11 PM, Jon Hunter wrote: > > On 11/07/2012 04:04 PM, Santosh Shilimkar wrote: >> On Wednesday 07 November 2012 01:01 PM, Jon Hunter wrote: >>> For OMAP2+ devices, when using DMTIMERs for system timers >>> (clock-events and >>> clock-source) the posted mode configuration of the timers is used. To >>> allow >>> the compiler to optimise the functions for configuring and reading the >>> system >>> timers, the posted flag variable is hard-coded with the value 1. To >>> make it >>> clear that posted mode is being used add some definitions so that it >>> is more >>> readable. >>> >>> Add separate definitions for the clock-events and clock-source timers >>> so that >>> we can change the posted mode of clock-events and clock-source >>> independently. >>> >>> Signed-off-by: Jon Hunter <jon-hunter@ti.com> >>> --- >>> arch/arm/mach-omap2/timer.c | 26 >>> +++++++++++++++++++------- >>> arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++ >>> 2 files changed, 23 insertions(+), 7 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >>> index 0758bae..28c6078 100644 >>> --- a/arch/arm/mach-omap2/timer.c >>> +++ b/arch/arm/mach-omap2/timer.c >>> @@ -82,6 +82,13 @@ >>> #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14 >>> #define NUMERATOR_DENUMERATOR_MASK 0xfffff000 >>> >>> +/* >>> + * For clock-events timer, always use posted mode to >>> + * minimise CPU overhead for configuring the timer. >>> + */ >>> +#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED >>> +#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED >>> + >> I don't see need of above defines. Just use OMAP_TIMER_POSTED directly >> with API. Rest of the patch looks fine. > > Yes that's possible, however, in patch #2, I am disabling posted mode > for clock-source (see changelog of patch #2 for details). Having these > #defines makes it easier to change the posted configuration. That was > the real motivation here. > Sure but that is more confusing because you are flipping the meaning of the macro. Better to specify direct argument to avoid the confusion. Regards Santosh
On 11/07/2012 04:18 PM, Santosh Shilimkar wrote: > On Wednesday 07 November 2012 04:11 PM, Jon Hunter wrote: >> >> On 11/07/2012 04:04 PM, Santosh Shilimkar wrote: >>> On Wednesday 07 November 2012 01:01 PM, Jon Hunter wrote: >>>> For OMAP2+ devices, when using DMTIMERs for system timers >>>> (clock-events and >>>> clock-source) the posted mode configuration of the timers is used. To >>>> allow >>>> the compiler to optimise the functions for configuring and reading the >>>> system >>>> timers, the posted flag variable is hard-coded with the value 1. To >>>> make it >>>> clear that posted mode is being used add some definitions so that it >>>> is more >>>> readable. >>>> >>>> Add separate definitions for the clock-events and clock-source timers >>>> so that >>>> we can change the posted mode of clock-events and clock-source >>>> independently. >>>> >>>> Signed-off-by: Jon Hunter <jon-hunter@ti.com> >>>> --- >>>> arch/arm/mach-omap2/timer.c | 26 >>>> +++++++++++++++++++------- >>>> arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++ >>>> 2 files changed, 23 insertions(+), 7 deletions(-) >>>> >>>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >>>> index 0758bae..28c6078 100644 >>>> --- a/arch/arm/mach-omap2/timer.c >>>> +++ b/arch/arm/mach-omap2/timer.c >>>> @@ -82,6 +82,13 @@ >>>> #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14 >>>> #define NUMERATOR_DENUMERATOR_MASK 0xfffff000 >>>> >>>> +/* >>>> + * For clock-events timer, always use posted mode to >>>> + * minimise CPU overhead for configuring the timer. >>>> + */ >>>> +#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED >>>> +#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED >>>> + >>> I don't see need of above defines. Just use OMAP_TIMER_POSTED directly >>> with API. Rest of the patch looks fine. >> >> Yes that's possible, however, in patch #2, I am disabling posted mode >> for clock-source (see changelog of patch #2 for details). Having these >> #defines makes it easier to change the posted configuration. That was >> the real motivation here. >> > Sure but that is more confusing because you are flipping > the meaning of the macro. Better to specify direct > argument to avoid the confusion. Hmmm ... I guess I don't see it that way. The intent was that the definitions OMAP_CLKxxx_POSTEDMODE described the posted configuration (ie. posted or non-posted) and a user could change/flip it if so desired. I can use the OMAP_TIMER_POSTED/NONPOSTED directly, but my concern with that was if someone wanted to changed the posted mode then they have to change it in multiple places and there is a chance they could miss one. This way, as long as I have it right to begin with, then no one should be able to screw it up :-) Cheers Jon
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index 0758bae..28c6078 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -82,6 +82,13 @@ #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14 #define NUMERATOR_DENUMERATOR_MASK 0xfffff000 +/* + * For clock-events timer, always use posted mode to + * minimise CPU overhead for configuring the timer. + */ +#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED +#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED + /* Clockevent code */ static struct omap_dm_timer clkev; @@ -107,7 +114,7 @@ static int omap2_gp_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST, - 0xffffffff - cycles, 1); + 0xffffffff - cycles, OMAP_CLKEVT_POSTEDMODE); return 0; } @@ -117,7 +124,7 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode, { u32 period; - __omap_dm_timer_stop(&clkev, 1, clkev.rate); + __omap_dm_timer_stop(&clkev, OMAP_CLKEVT_POSTEDMODE, clkev.rate); switch (mode) { case CLOCK_EVT_MODE_PERIODIC: @@ -125,10 +132,12 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode, period -= 1; /* Looks like we need to first set the load value separately */ __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG, - 0xffffffff - period, 1); + 0xffffffff - period, + OMAP_CLKEVT_POSTEDMODE); __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST, - 0xffffffff - period, 1); + 0xffffffff - period, + OMAP_CLKEVT_POSTEDMODE); break; case CLOCK_EVT_MODE_ONESHOT: break; @@ -358,7 +367,8 @@ static bool use_gptimer_clksrc; */ static cycle_t clocksource_read_cycles(struct clocksource *cs) { - return (cycle_t)__omap_dm_timer_read_counter(&clksrc, 1); + return (cycle_t)__omap_dm_timer_read_counter(&clksrc, + OMAP_CLKSRC_POSTEDMODE); } static struct clocksource clocksource_gpt = { @@ -372,7 +382,8 @@ static struct clocksource clocksource_gpt = { static u32 notrace dmtimer_read_sched_clock(void) { if (clksrc.reserved) - return __omap_dm_timer_read_counter(&clksrc, 1); + return __omap_dm_timer_read_counter(&clksrc, + OMAP_CLKSRC_POSTEDMODE); return 0; } @@ -454,7 +465,8 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id, BUG_ON(res); __omap_dm_timer_load_start(&clksrc, - OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1); + OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, + OMAP_CLKSRC_POSTEDMODE); setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate); if (clocksource_register_hz(&clocksource_gpt, clksrc.rate)) diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h index 348f855..835c3bdf 100644 --- a/arch/arm/plat-omap/include/plat/dmtimer.h +++ b/arch/arm/plat-omap/include/plat/dmtimer.h @@ -55,6 +55,10 @@ #define OMAP_TIMER_TRIGGER_OVERFLOW 0x01 #define OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE 0x02 +/* posted mode types */ +#define OMAP_TIMER_NONPOSTED 0x00 +#define OMAP_TIMER_POSTED 0x01 + /* timer capabilities used in hwmod database */ #define OMAP_TIMER_SECURE 0x80000000 #define OMAP_TIMER_ALWON 0x40000000
For OMAP2+ devices, when using DMTIMERs for system timers (clock-events and clock-source) the posted mode configuration of the timers is used. To allow the compiler to optimise the functions for configuring and reading the system timers, the posted flag variable is hard-coded with the value 1. To make it clear that posted mode is being used add some definitions so that it is more readable. Add separate definitions for the clock-events and clock-source timers so that we can change the posted mode of clock-events and clock-source independently. Signed-off-by: Jon Hunter <jon-hunter@ti.com> --- arch/arm/mach-omap2/timer.c | 26 +++++++++++++++++++------- arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++ 2 files changed, 23 insertions(+), 7 deletions(-)