linux-kernel - Re: [PATCH V2 2/2] firmware: arm_scmi: Skip adding bad duplicates

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Message-ID: <ZtgHw1RrZTZLr7Mw@hovoldconsulting.com>
Date: Wed, 4 Sep 2024 09:09:55 +0200
From: Johan Hovold <johan@...nel.org>
To: Sibi Sankar <quic_sibis@...cinc.com>
Cc: sudeep.holla@....com, cristian.marussi@....com,
	linux-kernel@...r.kernel.org, arm-scmi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
	konradybcio@...nel.org
Subject: Re: [PATCH V2 2/2] firmware: arm_scmi: Skip adding bad duplicates

On Wed, Sep 04, 2024 at 08:43:24AM +0530, Sibi Sankar wrote:
> Ensure that the bad duplicates reported by the platform firmware doesn't
> get added to the opp-tables.

Please expand on why this is an issue on Qualcomm platforms, these
entries aren't just "bad duplicates" if IIUC.

Also here, please add (examples of) the warnings I reported. During boot
of the x1e80100 crd, I see:

[    8.992956] cpu cpu4: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. New: freq: 3417600000, volt: 0, enabled: 1
[    9.021940] cpu cpu4: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. New: freq: 3417600000, volt: 0, enabled: 1
[    9.036171] cpu cpu8: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. New: freq: 3417600000, volt: 0, enabled: 1
[    9.036177] cpu cpu8: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. New: freq: 3417600000, volt: 0, enabled: 1

and during resume:

[   85.286615] cpu cpu4: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. N
ew: freq: 3417600000, volt: 0, enabled: 1
[   85.319849] cpu cpu4: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. N
ew: freq: 3417600000, volt: 0, enabled: 1
[   85.334686] debugfs: File 'cpu5' in directory 'opp' already present!
[   85.341399] debugfs: File 'cpu6' in directory 'opp' already present!
[   85.348016] debugfs: File 'cpu7' in directory 'opp' already present!

[   85.443093] cpu cpu8: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. N
ew: freq: 3417600000, volt: 0, enabled: 1
[   85.476595] cpu cpu8: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 3417600000, volt: 0, enabled: 1. N
ew: freq: 3417600000, volt: 0, enabled: 1
[   85.491645] debugfs: File 'cpu9' in directory 'opp' already present!
[   85.498409] debugfs: File 'cpu10' in directory 'opp' already present!
[   85.505187] debugfs: File 'cpu11' in directory 'opp' already present!

Please also add:

Reported-by: Johan Hovold <johan+linaro@...nel.org>
Link: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/

> Signed-off-by: Sibi Sankar <quic_sibis@...cinc.com>

But with this patch applied, instead of the above warnings I now get two
*errors* at boot:

	[    8.952173] cpu cpu4: EM: non-increasing freq: 0
        [    8.979460] cpu cpu8: EM: non-increasing freq: 0

Can you do something about that as well? At least make sure to highlight
this in the commit message as this is information that is needed to be
able to evaluate the patch.

Johan