Re: [RFC PATCH v5 v5 5/8] pmdomain/rockchip: cycle optional power-domain resets on power-on

[Philipp Zabel <p.zabel@pengutronix.de>]

On Mi, 2026-08-05 at 18:38 +1200, Jiaxing Hu wrote:
> Some Rockchip domains come out of power-on with their bus interface in
> an undefined state. On the RK3576 NPU this shows up as a hang on the
> first access after a cold power-on; the vendor kernel cycles the
> domain's resets at this point and that clears it.
> 
> Take the domain node's resets if it has any, and pulse them between
> releasing idle and restoring QoS. The resets are optional, so domains
> that do not declare any behave exactly as before.
> 
> Signed-off-by: Jiaxing Hu <gahing@gahingwoo.com>
> ---
>  drivers/pmdomain/rockchip/pm-domains.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/pmdomain/rockchip/pm-domains.c b/drivers/pmdomain/rockchip/pm-domains.c
> index e1857f878..82051f600 100644
> --- a/drivers/pmdomain/rockchip/pm-domains.c
> +++ b/drivers/pmdomain/rockchip/pm-domains.c
> @@ -19,6 +19,7 @@
>  #include <linux/of_clk.h>
>  #include <linux/clk.h>
>  #include <linux/delay.h>
> +#include <linux/reset.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/mfd/syscon.h>
> @@ -103,6 +104,7 @@ struct rockchip_pm_domain {
>  	struct clk_bulk_data *clks;
>  	struct device_node *node;
>  	struct regulator *supply;
> +	struct reset_control *resets;
>  };
>  
>  struct rockchip_pmu {
> @@ -688,6 +690,13 @@ static int rockchip_pd_power(struct rockchip_pm_domain *pd, bool power_on)
>  		if (pd->info->delay_us)
>  			udelay(pd->info->delay_us);
>  
> +		/* Optional: some domains need their resets cycled after power-on. */
> +		if (pd->resets) {
> +			reset_control_assert(pd->resets);
> +			udelay(10);
> +			reset_control_deassert(pd->resets);
> +		}
> +
>  		rockchip_pmu_restore_qos(pd);
>  	}
>  
> @@ -857,6 +866,14 @@ static int rockchip_pm_add_one_domain(struct rockchip_pmu *pmu,
>  	if (error)
>  		goto err_put_clocks;
>  
> +	pd->resets = of_reset_control_array_get_optional_exclusive(node);

Why is this using of_reset_control_array_get_optional_exclusive()
instead of devm_reset_control_array_get_optional_exclusive() when pd is
allocated with devm_kzalloc()?

> +	if (IS_ERR(pd->resets)) {
> +		error = PTR_ERR(pd->resets);
> +		dev_err(pmu->dev, "%pOFn: failed to get resets: %d\n", node, error);

dev_err_probe() to avoid printing on -EPROBE_DEFER.


regards
Philipp