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Subject: Re: [PATCH v2 1/3] soc: mtk-pm-domains: Fix the clock prepared issue
To:     Hsin-Yi Wang <hsinyi@chromium.org>
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        Rob Herring <robh+dt@kernel.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        chun-jie.chen@mediatek.corp-partner.google.com,
        Yong Wu <yong.wu@mediatek.com>
References: <20210601035905.2970384-1-hsinyi@chromium.org>
From:   Matthias Brugger <matthias.bgg@gmail.com>
Message-ID: <d13c74d7-845f-40bc-1969-2e419d49e78e@gmail.com>
Date:   Wed, 2 Jun 2021 14:15:57 +0200
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On 01/06/2021 05:59, Hsin-Yi Wang wrote:
> From: Weiyi Lu <weiyi.lu@mediatek.com>
> 
> In this new power domain driver, when adding one power domain
> it will prepare the dependent clocks at the same.
> 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
> 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.
> 
> Fixes: 59b644b01cf4 ("soc: mediatek: Add MediaTek SCPSYS power domains")
> Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Reviewed-by: chun-jie.chen <chun-jie.chen@mediatek.com>
> Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Both patches applied to v5.13-next/soc

Thanks!

> ---
>  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);
>  }
>  
>