linux-kernel - Re: [PATCH] Revert "clk: Fix invalid execution of clk_set

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Message-ID: <3fd004add188460bf2bdd1a718387c7f.sboyd@kernel.org>
Date: Mon, 02 Dec 2024 17:20:06 -0800
From: Stephen Boyd <sboyd@...nel.org>
To: Johan Hovold <johan+linaro@...nel.org>
Cc: Michael Turquette <mturquette@...libre.com>, linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org, regressions@...ts.linux.dev, Johan Hovold <johan+linaro@...nel.org>, Aishwarya TCV <aishwarya.tcv@....com>, Chuan Liu <chuan.liu@...ogic.com>, Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Subject: Re: [PATCH] Revert "clk: Fix invalid execution of clk_set_rate"

Quoting Johan Hovold (2024-12-02 02:06:21)
> This reverts commit 25f1c96a0e841013647d788d4598e364e5c2ebb7.
> 
> The offending commit results in errors like
> 
>         cpu cpu0: _opp_config_clk_single: failed to set clock rate: -22
> 
> spamming the logs on the Lenovo ThinkPad X13s and other Qualcomm
> machines when cpufreq tries to update the CPUFreq HW Engine clocks.
> 
> As mentioned in commit 4370232c727b ("cpufreq: qcom-hw: Add CPU clock
> provider support"):
> 
>         [T]he frequency supplied by the driver is the actual frequency
>         that comes out of the EPSS/OSM block after the DCVS operation.
>         This frequency is not same as what the CPUFreq framework has set
>         but it is the one that gets supplied to the CPUs after
>         throttling by LMh.
> 
> which seems to suggest that the driver relies on the previous behaviour
> of clk_set_rate().

I don't understand why a clk provider is needed there. Is anyone looking
into the real problem?

> 
> Since this affects many Qualcomm machines, let's revert for now.
> 
> Fixes: 25f1c96a0e84 ("clk: Fix invalid execution of clk_set_rate")
> Reported-by: Aishwarya TCV <aishwarya.tcv@....com>
> Link: https://lore.kernel.org/all/e2d83e57-ad07-411b-99f6-a4fc3c4534fa@arm.com/
> Cc: Chuan Liu <chuan.liu@...ogic.com>
> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
> Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
> ---

Applied to clk-fixes