Re: [PATCH] ARM: rockchip: keep reset control around

[Heiko Stuebner <heiko@sntech.de>]

Am Donnerstag, 21. Mai 2026, 23:09:15 Mitteleuropäische Sommerzeit schrieb Heiko Stuebner:
> Do not put the reset control, retain exclusive control over it.
> After turning on a CPU, the corresponding reset line must stay
> deasserted.
> 
> This also avoids calling reset_control_put() before workqueues
> are operational.
> 
> Fixes: 78ebbff6d1a0 ("reset: handle removing supplier before consumers")
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> Tested-by: Steven Price <steven.price@arm.com>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Forgot to add Bartosz to the Cc list, sorry


Heiko

> ---
>  arch/arm/mach-rockchip/platsmp.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
> index f432d22bfed8..f659d894bfae 100644
> --- a/arch/arm/mach-rockchip/platsmp.c
> +++ b/arch/arm/mach-rockchip/platsmp.c
> @@ -34,6 +34,7 @@ static int ncores;
>  
>  static struct regmap *pmu;
>  static int has_pmu = true;
> +static struct reset_control *cpu_rstc[4];
>  
>  static int pmu_power_domain_is_on(int pd)
>  {
> @@ -64,9 +65,11 @@ 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);
> +	struct reset_control *rstc;
>  	int ret;
>  
> +	rstc = pd < ARRAY_SIZE(cpu_rstc) ? cpu_rstc[pd] : ERR_PTR(-EINVAL);
> +
>  	if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
>  		pr_err("%s: could not get reset control for core %d\n",
>  		       __func__, pd);
> @@ -100,11 +103,8 @@ static int pmu_set_power_domain(int pd, bool on)
>  		}
>  	}
>  
> -	if (!IS_ERR(rstc)) {
> -		if (on)
> -			reset_control_deassert(rstc);
> -		reset_control_put(rstc);
> -	}
> +	if (!IS_ERR(rstc) && on)
> +		reset_control_deassert(rstc);
>  
>  	return 0;
>  }
> @@ -312,6 +312,10 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
>  		ncores = ((l2ctlr >> 24) & 0x3) + 1;
>  	}
>  
> +	/* Collect cpu core reset control for each core */
> +	for (i = 0; i < ncores; i++)
> +		cpu_rstc[i] = rockchip_get_core_reset(i);
> +
>  	/* Make sure that all cores except the first are really off */
>  	for (i = 1; i < ncores; i++)
>  		pmu_set_power_domain(0 + i, false);
>