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@xxxxxx> >>>> --- >>>> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
