Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: rnayak=codeaurora.org@mg.codeaurora.org
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3C12DC433D3
Subject: Re: [PATCH 1/2] soc: qcom: rpmhpd: Use corner in power_off
To:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc:     linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210703005416.2668319-1-bjorn.andersson@linaro.org>
 <20210703005416.2668319-2-bjorn.andersson@linaro.org>
From:   Rajendra Nayak <rnayak@codeaurora.org>
Message-ID: <cacd1a1f-01c8-b913-23e5-538a772cd118@codeaurora.org>
Date:   Mon, 5 Jul 2021 09:56:47 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <20210703005416.2668319-2-bjorn.andersson@linaro.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 7/3/2021 6:24 AM, Bjorn Andersson wrote:
> rpmhpd_aggregate_corner() takes a corner as parameter, but in
> rpmhpd_power_off() the code requests the level of the first corner
> instead.
> 
> In all (known) current cases the first corner has level 0, so this
> change should be a nop, but in case that there's a power domain with a
> non-zero lowest level this makes sure that rpmhpd_power_off() actually
> requests the lowest level - which is the closest to "power off" we can
> get.
> 
> While touching the code, also skip the unnecessary zero-initialization
> of "ret".
> 
> Fixes: 279b7e8a62cc ("soc: qcom: rpmhpd: Add RPMh power domain driver")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>   drivers/soc/qcom/rpmhpd.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/soc/qcom/rpmhpd.c b/drivers/soc/qcom/rpmhpd.c
> index 2daa17ba54a3..fa209b479ab3 100644
> --- a/drivers/soc/qcom/rpmhpd.c
> +++ b/drivers/soc/qcom/rpmhpd.c
> @@ -403,12 +403,11 @@ static int rpmhpd_power_on(struct generic_pm_domain *domain)
>   static int rpmhpd_power_off(struct generic_pm_domain *domain)
>   {
>   	struct rpmhpd *pd = domain_to_rpmhpd(domain);
> -	int ret = 0;
> +	int ret;
>   
>   	mutex_lock(&rpmhpd_lock);
>   
> -	ret = rpmhpd_aggregate_corner(pd, pd->level[0]);
> -
> +	ret = rpmhpd_aggregate_corner(pd, 0);

This won't work for cases where pd->level[0] != 0, rpmh would just ignore this and keep the
resource at whatever corner it was previously at.
(unless command DB tells you a 0 is 'valid' for a resource, sending a 0 is a nop)
The right thing to do is to send in whatever command DB tells you is the lowest level that's valid,
which is pd->level[0].


>   	if (!ret)
>   		pd->enabled = false;
>   
> 

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation