ARM: OMAP2+: am43xx: enable GENERIC_CLOCKEVENTS_BROADCAST

System will misbehave in the following case:
- AM43XX only build (UP);
- CONFIG_CPU_IDLE=y
- ARM TWD timer enabled and selected as clockevent device.

In the above case, It's expected that broadcast timer will be used as
backup timer when CPUIdle will put MPU in low power states where ARM
TWD will stop and lose its context. But, the CONFIG_SMP might not be
selected when kernel is built for AM43XX SoC only and, as result,
GENERIC_CLOCKEVENTS_BROADCAST option will not be selected also. This
will break CPUIdle and System will stuck in low power states.

Hence, fix it by selecting GENERIC_CLOCKEVENTS_BROADCAST option for
AM43XX SoCs always and add empty tick_broadcast() function
implementation - no need to send any IPI on UP. After this change
timer1 will be selected as broadcast timer the same way as for SMP,
and CPUIdle will work properly.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 4b4371db5799cc8c5d726281e0834277304404f5..32a0086f967d37c3375fe95d71972efaec7fd3da 100644 (file)
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -65,6 +65,7 @@ config SOC_AM43XX
        select MACH_OMAP_GENERIC
        select MIGHT_HAVE_CACHE_L2X0
        select HAVE_ARM_SCU
+       select GENERIC_CLOCKEVENTS_BROADCAST
 
 config SOC_DRA7XX
        bool "TI DRA7XX"

diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index b18ebbefae09577e20b19e53167aca5ef11b8d86..f86692dbcfd56efce7250b3a659891ad57a45725 100644 (file)
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -320,6 +320,12 @@ static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
        return r;
 }
 
+#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
+void tick_broadcast(const struct cpumask *mask)
+{
+}
+#endif
+
 static void __init omap2_gp_clockevent_init(int gptimer_id,
                                                const char *fck_source,
                                                const char *property)