Subject: [PATCH v5 1/3] ARM: rockchip: fix the CPU soft reset

From: [email-masked] (Caesar Wang)
Date: Mon, 08 Jun 2015 15:51:15 +0800

? 2015?06?08? 15:11, 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))
>      wait_for_power_domain_to_turn_off
> CPU on:
>      regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0)
>      wait_for_power_domain_to_turn_on
>      reset_control_deassert
>
> This is needed for stressing CPU up/down, as per:
>      cd /sys/devices/system/cpu/
>      for i in $(seq 10000); 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
>      .......
> or others similar log:
>      .......
>      [ 4072.454453] CPU1: shutdown
>      [ 4072.504436] CPU2: shutdown
>      [ 4072.554426] CPU3: shutdown
>      [ 4072.577827] CPU1: Booted secondary processor
>      [ 4072.582611] CPU2: Booted secondary processor
>      [ 4072.587426] CPU3: Booted secondary processor
>      <hang>
>
> Signed-off-by: Caesar Wang <[email-masked]>
> Reviewed-by: Doug Anderson <[email-masked]>
>
> Changes in v5:
>      - back to v2 cpu on/off flow, As Heiko point out in patch v3.
>      - delay more time in rockchip_boot_secondary().
>      From CPU up/down tests, Needed more time to complete CPU process.
>      In order to ensure a more, Here that be delayed 1ms.
>
> Changes in v4:
>      - Add reset_control_put(rstc) for the non-error case.
>
> Changes in v3:
>      - FIx the PATCH v2, it doesn't work on chromium 3.14.
>
> Changes in v2:
>      - As Heiko suggestion, re-adjust the cpu on/off flow.
>      CPU off:
>      reset_control_assert
>      regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), BIT(pd))
>      wait_for_power_domain_to_turn_off
>      CPU on:
>      regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0)
>      wait_for_power_domain_to_turn_on
>      reset_control_deassert

Sorry for making a mistake in here.
'Series-changes' isn't  that 'Changes in' with patman.

That's why the change log can't be 'below the cut'.

> ---
>
>   arch/arm/mach-rockchip/platsmp.c | 18 ++++++++++--------
>   1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
> index 5b4ca3c..bd40852 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 +81,15 @@ 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 +108,12 @@ 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;
>   }
>   
> @@ -148,7 +150,7 @@ static int __cpuinit rockchip_boot_secondary(unsigned int cpu,
>   		 * sram_base_addr + 4: 0xdeadbeaf
>   		 * sram_base_addr + 8: start address for pc
>   		 * */
> -		udelay(10);
> +		mdelay(1);
>   		writel(virt_to_phys(rockchip_secondary_startup),
>   			sram_base_addr + 8);
>   		writel(0xDEADBEAF, sram_base_addr + 4);