[PATCH] omap: timer: Set dmtimer used as clocksource in autoreload mode

[PATCH] omap: timer: Set dmtimer used as clocksource in autoreload mode

[Hemant Pedanekar]

If CONFIG_OMAP_32K_TIMER is not selected and dmtimer is used as clocksource, the
timer stops counting once overflow occurs as it was not set in autoreload mode.
This results into timekeeping failure: for example, 'sleep 1' at the shell after
the timer counter overflow would hang.

This patch sets up autoreload when starting the clocksource timer which fixes
the above issue.

Signed-off-by: Hemant Pedanekar <hemantp@ti.com>
---
 arch/arm/mach-omap2/timer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index e964072..796b935 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -293,7 +293,7 @@ static void __init omap2_gp_clocksource_init(int gptimer_id,
 	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
 		gptimer_id, clksrc.rate);
 
-	__omap_dm_timer_load_start(clksrc.io_base, OMAP_TIMER_CTRL_ST, 0, 1);
+	omap_dm_timer_set_load_start(&clksrc, 1, 0);
 	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate);
 
 	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
-- 
1.7.3.5

[PATCH] omap: timer: Set dmtimer used as clocksource in autoreload mode

[Tony Lindgren]

* Hemant Pedanekar <hemantp@ti.com> [110809 20:46]:
> If CONFIG_OMAP_32K_TIMER is not selected and dmtimer is used as clocksource, the
> timer stops counting once overflow occurs as it was not set in autoreload mode.
> This results into timekeeping failure: for example, 'sleep 1' at the shell after
> the timer counter overflow would hang.
> 
> This patch sets up autoreload when starting the clocksource timer which fixes
> the above issue.
> 
> Signed-off-by: Hemant Pedanekar <hemantp@ti.com>
> ---
>  arch/arm/mach-omap2/timer.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
> index e964072..796b935 100644
> --- a/arch/arm/mach-omap2/timer.c
> +++ b/arch/arm/mach-omap2/timer.c
> @@ -293,7 +293,7 @@ static void __init omap2_gp_clocksource_init(int gptimer_id,
>  	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
>  		gptimer_id, clksrc.rate);
>  
> -	__omap_dm_timer_load_start(clksrc.io_base, OMAP_TIMER_CTRL_ST, 0, 1);
> +	omap_dm_timer_set_load_start(&clksrc, 1, 0);
>  	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate);
>  
>  	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))

You should be able to just set the autoreload mode by changing to use
OMAP_TIMER_CTRL_POSTED | OMAP_TIMER_CTRL_AR in the __omap_dm_timer_load_start
above.

This avoids calling something that might be a loadable module eventually.

Regards,

Tony

[PATCH] omap: timer: Set dmtimer used as clocksource in autoreload mode

[Pedanekar, Hemant]

Tony Lindgren wrote on Wednesday, August 10, 2011 5:21 PM:

> * Hemant Pedanekar <hemantp@ti.com> [110809 20:46]:
>> If CONFIG_OMAP_32K_TIMER is not selected and dmtimer is used as
>> clocksource, the timer stops counting once overflow occurs as it was not
>> set in autoreload mode. This results into timekeeping failure: for
>> example, 'sleep 1' at the shell after the timer counter overflow would
>> hang. 
>> 
>> This patch sets up autoreload when starting the clocksource timer which
>> fixes the above issue. 
>> 
>> Signed-off-by: Hemant Pedanekar <hemantp@ti.com>
>> ---
>>  arch/arm/mach-omap2/timer.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>> 
>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
>> index e964072..796b935 100644 --- a/arch/arm/mach-omap2/timer.c
>> +++ b/arch/arm/mach-omap2/timer.c
>> @@ -293,7 +293,7 @@ static void __init
> omap2_gp_clocksource_init(int gptimer_id,
>>  	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",  		gptimer_id,
>> clksrc.rate); 
>> 
>> -	__omap_dm_timer_load_start(clksrc.io_base, OMAP_TIMER_CTRL_ST, 0, 1);
>> +	omap_dm_timer_set_load_start(&clksrc, 1, 0);
>>  	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate);
>> 
>>  	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
> 
> You should be able to just set the autoreload mode by changing to use
> OMAP_TIMER_CTRL_POSTED | OMAP_TIMER_CTRL_AR in the
> __omap_dm_timer_load_start
> above.
> 
> This avoids calling something that might be a loadable module eventually.
> 
> Regards,
> 
> Tony

Yes, that would be better - I didn't think about loadable module option.

Thanks.
   Hemant