Re: [PATCH 1/3] soc: mtk-pm-domains: Fix the clock prepared issue

[Enric Balletbo Serra <eballetbo@gmail.com>]

Hi Hsin-Yi,

Thank you for the patch.

Missatge de Hsin-Yi Wang <hsinyi@chromium.org> del dia dl., 31 de maig
2021 a les 6:35:
>
> From: Weiyi Lu <weiyi.lu@mediatek.com>
>
> In this new power domain driver, when adding one power domain
> it will prepare the depenedent clocks at the same.

Typo: s/depenedent/dependent/

> So we only do clk_bulk_enable/disable control during power ON/OFF.
> When system suspend, the pm runtime framework will forcely power off
> power domains. However, the dependent clocks are disabled but kept
> preapred.

Typo: s/preapred/prepared

>
> In MediaTek clock drivers, PLL would be turned ON when we do
> clk_bulk_prepare control.
>
> Clock hierarchy:
> PLL -->
>        DIV_CK -->
>                  CLK_MUX
>                  (may be dependent clocks)
>                          -->
>                              SUBSYS_CG
>                              (may be dependent clocks)
>
> It will lead some unexpected clock states during system suspend.
> This patch will fix by doing prepare_enable/disable_unprepare on
> dependent clocks at the same time while we are going to power on/off
> any power domain.
>

I think it would be nice to have a Fixes tag here, so this can be
backported more easily.

> Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>

Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

> ---
>  drivers/soc/mediatek/mtk-pm-domains.c | 31 +++++++--------------------
>  1 file changed, 8 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> index 0af00efa0ef8..536d8c64b2b4 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -211,7 +211,7 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>         if (ret)
>                 return ret;
>
> -       ret = clk_bulk_enable(pd->num_clks, pd->clks);
> +       ret = clk_bulk_prepare_enable(pd->num_clks, pd->clks);
>         if (ret)
>                 goto err_reg;
>
> @@ -229,7 +229,7 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>         regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ISO_BIT);
>         regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
>
> -       ret = clk_bulk_enable(pd->num_subsys_clks, pd->subsys_clks);
> +       ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
>         if (ret)
>                 goto err_pwr_ack;
>
> @@ -246,9 +246,9 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>  err_disable_sram:
>         scpsys_sram_disable(pd);
>  err_disable_subsys_clks:
> -       clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
> +       clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
>  err_pwr_ack:
> -       clk_bulk_disable(pd->num_clks, pd->clks);
> +       clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
>  err_reg:
>         scpsys_regulator_disable(pd->supply);
>         return ret;
> @@ -269,7 +269,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
>         if (ret < 0)
>                 return ret;
>
> -       clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
> +       clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
>
>         /* subsys power off */
>         regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
> @@ -284,7 +284,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
>         if (ret < 0)
>                 return ret;
>
> -       clk_bulk_disable(pd->num_clks, pd->clks);
> +       clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
>
>         scpsys_regulator_disable(pd->supply);
>
> @@ -405,14 +405,6 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>                 pd->subsys_clks[i].clk = clk;
>         }
>
> -       ret = clk_bulk_prepare(pd->num_clks, pd->clks);
> -       if (ret)
> -               goto err_put_subsys_clocks;
> -
> -       ret = clk_bulk_prepare(pd->num_subsys_clks, pd->subsys_clks);
> -       if (ret)
> -               goto err_unprepare_clocks;
> -
>         /*
>          * Initially turn on all domains to make the domains usable
>          * with !CONFIG_PM and to get the hardware in sync with the
> @@ -427,7 +419,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>                 ret = scpsys_power_on(&pd->genpd);
>                 if (ret < 0) {
>                         dev_err(scpsys->dev, "%pOF: failed to power on domain: %d\n", node, ret);
> -                       goto err_unprepare_clocks;
> +                       goto err_put_subsys_clocks;
>                 }
>         }
>
> @@ -435,7 +427,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>                 ret = -EINVAL;
>                 dev_err(scpsys->dev,
>                         "power domain with id %d already exists, check your device-tree\n", id);
> -               goto err_unprepare_subsys_clocks;
> +               goto err_put_subsys_clocks;
>         }
>
>         if (!pd->data->name)
> @@ -455,10 +447,6 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>
>         return scpsys->pd_data.domains[id];
>
> -err_unprepare_subsys_clocks:
> -       clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
> -err_unprepare_clocks:
> -       clk_bulk_unprepare(pd->num_clks, pd->clks);
>  err_put_subsys_clocks:
>         clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
>  err_put_clocks:
> @@ -537,10 +525,7 @@ static void scpsys_remove_one_domain(struct scpsys_domain *pd)
>                         "failed to remove domain '%s' : %d - state may be inconsistent\n",
>                         pd->genpd.name, ret);
>
> -       clk_bulk_unprepare(pd->num_clks, pd->clks);
>         clk_bulk_put(pd->num_clks, pd->clks);
> -
> -       clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
>         clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
>  }
>
> --
> 2.32.0.rc0.204.g9fa02ecfa5-goog
>
>
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