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Message-ID: <76b652c8-041c-49d6-9804-2781fe2ccfe3@linaro.org>
Date:   Thu, 19 Oct 2023 13:22:33 +0200
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Subject: Re: [PATCH v2 01/11] clk: qcom: ipq8074: drop the CLK_SET_RATE_PARENT
 flag from PLL clocks
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To:     Stephen Boyd <sboyd@kernel.org>, Andy Gross <agross@kernel.org>,
        Anusha Rao <quic_anusha@quicinc.com>,
        Bjorn Andersson <andersson@kernel.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Devi Priya <quic_devipriy@quicinc.com>,
        Gokul Sriram Palanisamy <quic_gokulsri@quicinc.com>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        Kathiravan Thirumoorthy <quic_kathirav@quicinc.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        Sricharan Ramabadhran <quic_srichara@quicinc.com>,
        Varadarajan Narayanan <quic_varada@quicinc.com>
Cc:     linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        stable@vger.kernel.org
References: <20230913-gpll_cleanup-v2-0-c8ceb1a37680@quicinc.com>
 <20230913-gpll_cleanup-v2-1-c8ceb1a37680@quicinc.com>
 <76f3bc23-8677-42bd-a3a5-43b17cbe552e@linaro.org>
 <c3dfeecf5cde513cf675b2f1a382f7a4.sboyd@kernel.org>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <c3dfeecf5cde513cf675b2f1a382f7a4.sboyd@kernel.org>
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Precedence: bulk


On 10/19/23 02:16, Stephen Boyd wrote:
> Quoting Konrad Dybcio (2023-09-15 05:19:56)
>> On 14.09.2023 08:59, Kathiravan Thirumoorthy wrote:
>>> GPLL, NSS crypto PLL clock rates are fixed and shouldn't be scaled based
>>> on the request from dependent clocks. Doing so will result in the
>>> unexpected behaviour. So drop the CLK_SET_RATE_PARENT flag from the PLL
>>> clocks.
>>>
>>> Cc: stable@vger.kernel.org
>>> Fixes: b8e7e519625f ("clk: qcom: ipq8074: add remaining PLL’s")
>>> Signed-off-by: Kathiravan Thirumoorthy <quic_kathirav@quicinc.com>
>>> ---
>> Stephen, do you think there should be some sort of error
>> or at least warning thrown when SET_RATE_PARENT is used with
>> RO ops?
>>
> 
> Sure? How would that be implemented?
drivers/clk/clk.c : static void clk_change_rate()

if (!skip_set_rate && core->ops->set_rate)
	core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);

->

if (!skip_set_rate) {
	if (core->ops->set_rate)
		core->ops->set_rate(core->hw, core->new_rate,
				    best_parent_rate);
	else
		pr_err("bad idea");
}

Konrad