linux-kernel - Re: [PATCH 3/3] clk: qcom: gcc-sc7280: Update the .pwrsts for usb gdsc

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Message-ID: <YyF+IuoDjBZzEQxO@hovoldconsulting.com>
Date:   Wed, 14 Sep 2022 09:09:22 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Rajendra Nayak <quic_rjendra@...cinc.com>
Cc:     andersson@...nel.org, agross@...nel.org,
        konrad.dybcio@...ainline.org, mturquette@...libre.com,
        sboyd@...nel.org, mka@...omium.org, johan+linaro@...nel.org,
        quic_kriskura@...cinc.com, dianders@...omium.org,
        linux-clk@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] clk: qcom: gcc-sc7280: Update the .pwrsts for usb
 gdsc

On Thu, Sep 01, 2022 at 03:47:56PM +0530, Rajendra Nayak wrote:
> USB on sc7280 cannot support wakeups from low power states
> if the GDSC is turned OFF. Update the .pwrsts for usb GDSC so it
> only transitions to RET in low power.

It seems this isn't just needed for wakeup to work. On both sc7280 and
sc8280xp the controller doesn't resume properly if the domain has been
powered off (i.e. regardless of whether wakeup is enabled or not).

Are you sure there's no state that needs to be retained regardless of
the wakeup setting?

> Signed-off-by: Rajendra Nayak <quic_rjendra@...cinc.com>
> ---
>  drivers/clk/qcom/gcc-sc7280.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/qcom/gcc-sc7280.c b/drivers/clk/qcom/gcc-sc7280.c
> index 7ff64d4d5920..de29a034e725 100644
> --- a/drivers/clk/qcom/gcc-sc7280.c
> +++ b/drivers/clk/qcom/gcc-sc7280.c
> @@ -3126,7 +3126,7 @@ static struct gdsc gcc_usb30_prim_gdsc = {
>  	.pd = {
>  		.name = "gcc_usb30_prim_gdsc",
>  	},
> -	.pwrsts = PWRSTS_OFF_ON,
> +	.pwrsts = PWRSTS_RET_ON,
>  	.flags = VOTABLE,
>  };

And what about gcc_usb30_sec_gdsc?

Johan