Hi Caesar,
Am Freitag, 5. Juni 2015, 23:11:42 schrieb Caesar Wang:
> We need different orderings when turning a core on and turning a core
> off. In one case we need to assert reset before turning power off.
> In ther other case we need to turn power on and the deassert reset.
>
> In general, the correct flow is:
>
> CPU off:
> reset_control_assert
> regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), BIT(pd))
> CPU on:
> regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0)
> reset_control_deassert
>
> This is needed for stressing CPU up/down, as per:
> cd /sys/devices/system/cpu/
> for i in $(seq 1000); do
> echo "================= $i ============"
> for j in $(seq 100); do
> while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat
> cpu3/online)" != "000"" ]] echo 0 > cpu1/online
> echo 0 > cpu2/online
> echo 0 > cpu3/online
> done
> while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat
> cpu3/online)" != "111" ]]; do echo 1 > cpu1/online
> echo 1 > cpu2/online
> echo 1 > cpu3/online
> done
> done
> done
>
> The following is reproducile log:
> [34466.186812] PM: noirq suspend of devices complete after 0.669 msecs
> [34466.186824] Disabling non-boot CPUs ...
> [34466.187509] CPU1: shutdown
> [34466.188672] CPU2: shutdown
> [34473.736627] Kernel panic - not syncing:Watchdog detected hard LOCKUP
> on cpu 0 .......
>
> Signed-off-by: Caesar Wang <wxt at rock-chips.com>
> ---
could we do this something like the shown below instead?
Here the deassertion of the reset really happens after we are sure the
power-domain is on
-------------- 8< ---------------
diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
index 5b4ca3c..ee5dbad6 100644
--- a/arch/arm/mach-rockchip/platsmp.c
+++ b/arch/arm/mach-rockchip/platsmp.c
@@ -72,6 +72,7 @@ static struct reset_control *rockchip_get_core_reset(int cpu)
static int pmu_set_power_domain(int pd, bool on)
{
u32 val = (on) ? 0 : BIT(pd);
+ struct reset_control *rstc = rockchip_get_core_reset(pd);
int ret;
/*
@@ -80,20 +81,16 @@ static int pmu_set_power_domain(int pd, bool on)
* processor is powered down.
*/
if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
- struct reset_control *rstc = rockchip_get_core_reset(pd);
-
+ /* We only require the reset on the RK3288 at the moment */
if (IS_ERR(rstc)) {
pr_err("%s: could not get reset control for core %d\n",
__func__, pd);
return PTR_ERR(rstc);
}
- if (on)
- reset_control_deassert(rstc);
- else
+ if (!on)
reset_control_assert(rstc);
- reset_control_put(rstc);
}
ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
@@ -112,6 +109,12 @@ static int pmu_set_power_domain(int pd, bool on)
}
}
+ if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9 && on)
+ reset_control_deassert(rstc);
+
+ if (!IS_ERR(rstc))
+ reset_control_put(rstc);
+
return 0;
}
-------------- 8< ---------------
