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

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

* Hemant Pedanekar [off-list ref] [110809 20:46]:

quoted

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 <redacted>
---
 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,

quoted

 	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