linux-kernel - Re: [PATCH v3 15/16] soc: mediatek: pm-domains: Add default power off flag

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Date:   Tue, 27 Oct 2020 11:53:34 +0100
From:   Matthias Brugger <matthias.bgg@...il.com>
To:     Enric Balletbo i Serra <enric.balletbo@...labora.com>,
        linux-kernel@...r.kernel.org
Cc:     drinkcat@...omium.org, hsinyi@...omium.org,
        Collabora Kernel ML <kernel@...labora.com>,
        fparent@...libre.com, weiyi.lu@...iatek.com,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH v3 15/16] soc: mediatek: pm-domains: Add default power off
 flag



On 26/10/2020 18:55, Enric Balletbo i Serra wrote:
> From: Weiyi Lu <weiyi.lu@...iatek.com>
> 
> For some power domain, like conn on MT8192, it should be default OFF.
> Because the power on/off control relies the function of connectivity chip
> and its firmware. And if project choose other chip vendor solution,
> those necessary connectivity functions will not provided.
> 
> Signed-off-by: Weiyi Lu <weiyi.lu@...iatek.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@...labora.com>
> ---
> 
> Changes in v3: None
> Changes in v2: None
> 
>   drivers/soc/mediatek/mtk-pm-domains.c | 23 +++++++++++++++++------
>   drivers/soc/mediatek/mtk-pm-domains.h |  1 +
>   2 files changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> index 63993076a544..fe0e955076a0 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -378,10 +378,16 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>   	 * software.  The unused domains will be switched off during
>   	 * late_init time.
>   	 */
> -	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;
> +	if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF)) {
> +		if (scpsys_domain_is_on(pd))
> +			dev_warn(scpsys->dev,
> +				 "%pOF: A default off power domain has been ON\n", node);
> +	} else {
> +		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;
> +		}
>   	}
>   
>   	if (scpsys->domains[id]) {
> @@ -395,7 +401,11 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>   	pd->genpd.power_off = scpsys_power_off;
>   	pd->genpd.power_on = scpsys_power_on;
>   
> -	pm_genpd_init(&pd->genpd, NULL, false);
> +	if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
> +		pm_genpd_init(&pd->genpd, NULL, true);
> +	else
> +		pm_genpd_init(&pd->genpd, NULL, false);
> +
>   	scpsys->domains[id] = &pd->genpd;
>   
>   	return scpsys->pd_data.domains[id];
> @@ -478,7 +488,8 @@ 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);
>   
> -	scpsys_power_off(&pd->genpd);
> +	if (!MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
> +		scpsys_power_off(&pd->genpd);

OK, so you merged Weiyi's patches in this series :)

So same comment here: Does it really hurt if we turn-off a already turned-off 
power domain? Or can we get rid of this check?

Regards,
Matthias

>   
>   	clk_bulk_unprepare(pd->num_clks, pd->clks);
>   	clk_bulk_put(pd->num_clks, pd->clks);
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h b/drivers/soc/mediatek/mtk-pm-domains.h
> index 2ad213be84a5..0fa6a938b40c 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.h
> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
> @@ -6,6 +6,7 @@
>   #define MTK_SCPD_ACTIVE_WAKEUP		BIT(0)
>   #define MTK_SCPD_FWAIT_SRAM		BIT(1)
>   #define MTK_SCPD_SRAM_ISO		BIT(2)
> +#define MTK_SCPD_KEEP_DEFAULT_OFF	BIT(3)
>   #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
>   
>   #define SPM_VDE_PWR_CON			0x0210
>