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Message-ID: <19eceba8-dfc3-40d0-a681-8c47a0248cfd@linaro.org>
Date: Tue, 9 Jan 2024 10:33:39 +0100
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Subject: Re: [PATCH 09/18] clk: qcom: gcc-sm8250: Set delay for Venus CLK
 resets
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To: Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
 Bjorn Andersson <andersson@kernel.org>,
 Michael Turquette <mturquette@baylibre.com>, Stephen Boyd
 <sboyd@kernel.org>, Philipp Zabel <p.zabel@pengutronix.de>
Cc: Marijn Suijten <marijn.suijten@somainline.org>,
 linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
 linux-kernel@vger.kernel.org, Dikshita Agarwal <quic_dikshita@quicinc.com>,
 Vikash Garodia <quic_vgarodia@quicinc.com>,
 Manivannan Sadhasivam <mani@kernel.org>
References: <20240105-topic-venus_reset-v1-0-981c7a624855@linaro.org>
 <20240105-topic-venus_reset-v1-9-981c7a624855@linaro.org>
 <0cbedc75-cacf-43f8-a1f9-284546ad548a@linaro.org>
From: Konrad Dybcio <konrad.dybcio@linaro.org>
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On 1/9/24 01:34, Bryan O'Donoghue wrote:
> On 08/01/2024 12:32, Konrad Dybcio wrote:
>> Some Venus resets may require more time when toggling. Describe that.
> 
> May or does ?
> 
> I'd prefer a strong declaration of where this value came from and why its being added.
> 
> May is ambiguous.
> 
> "Downstream has a 150 us delay for this. My own testing shows this to be necessary in upstream"

Alright

> 
> Later commits want to add a 1000 us delay. Have all of these delays been tested ?

No, we don't support Venus on many of the newer SoCs..


> 
> If not please describe where the values come.

They come from the downstream Venus driver as you mentioned.
I checked a couple different downstream SoC kernel trees and
tried to assign the values based on what I found in a kernel
for that platform. Some are fairly educated guesses.

Konrad