Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 29 May 2023 10:28:54 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
        Stephen Boyd <sboyd@kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] opp: Provide a function for just setting bandwidth
Message-ID: <20230529045854.gh36k5my4i35jspc@vireshk-i7>
References: <20230526-topic-opp_bw-v1-1-e881091363af@linaro.org>
 <20230526105320.pfnu3oxl2cm37ot7@vireshk-i7>
 <f8731d93-b335-6d9a-183c-34a652f45455@linaro.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <f8731d93-b335-6d9a-183c-34a652f45455@linaro.org>
Precedence: bulk

On 26-05-23, 12:59, Konrad Dybcio wrote:
> There are some users which have tight power sequencing requirements,
> like the Qualcomm Adreno GPU.
> 
> Dropping the entire OPP kills clocks, bw and required-opps at once,
> but on certain Adrenos we need something like:
> 
> 
> disable memory clock (clk)
> disable all other clocks, including the opp-managed core clock (clk_bulk)
> kill one, fully manually controlled genpd (manual runtime pm)
> remove bus vote (func proposed in this patch)
> kill another genpd (manual runtime pm)
> kill the opp-managed genpd (automatic pm calls)
> 
> Changing the order kills the chip until you reboot the whole board and
> setting freq=0 using dev_pm_opp_set_rate doesn't drop the bw vote.

I am a bit confused now.

What's the exact problem with dev_pm_opp_set_rate(dev, 0) ? It does set the
bandwidth too, from what I can see.

-- 
viresh