linux-kernel - Re: [PATCH v2 2/2] irqchip: Add Qualcomm MPM controller driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e7a70e7d-c9b6-c10d-23c8-dd5ca74cc4dd@quicinc.com>
Date:   Tue, 30 Nov 2021 14:34:28 +0530
From:   Maulik Shah <quic_mkshah@...cinc.com>
To:     Shawn Guo <shawn.guo@...aro.org>
CC:     Marc Zyngier <maz@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Bjorn Andersson" <bjorn.andersson@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Loic Poulain <loic.poulain@...aro.org>,
        <devicetree@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] irqchip: Add Qualcomm MPM controller driver

Hi,

On 11/30/2021 2:14 PM, Shawn Guo wrote:
> On Tue, Nov 30, 2021 at 01:56:02PM +0530, Maulik Shah wrote:
>> Hi,
>>
>> On 11/29/2021 7:15 PM, Shawn Guo wrote:
>>>> This is not limited to suspend, you will need to notify RPM during deepest
>>>> cpu idle state entry as well, since MPM may be monitoring interrupts in that
>>>> case too.
>>> Yeah, I was trying to test this MPM driver with cpuidle, but failed to
>>> see the SoC get into vlow/vmin state from cpuidle.
>> In a few cases SoC can enter vmin/vlow from cpuidle one is from static
>> screen on.
>>
>>> Do you have any
>>> suggestion how I should test it properly?
>> Suspend resume (use "s2idle" and not "deep" mode on upstream kernel) is one
>> good method, but you will have to make sure all drivers have removed votes
>> on xo clock when entering suspend.
>> Also need to make sure other subsystem like modem is in power collaspe (look
>> at the internal master stats driver to know if other subsystems entering to
>> low power mode or not).
> I have already been able to trigger a vmin sleep with s2idle by doing:
>
>   $ echo mem > /sys/power/state
>
> My question is how I can get a vmin sleep in idle case, so that MPM
> driver can be tested in both suspend and idle context.
>
> Shawn

In a few cases SoC can enter vmin/vlow from cpuidle one is from static screen on.
you can turn on display and set display off timeout to maximum (30 minutes) in android phone and then just leave the device idle for few minutes

another possible way (if display is not present) is to take some wake_lock (write something to /sys/power/wake_lock) and disconnect USB and leave the device idle for few minutes.
since taking wake_lock device will not enter suspend, cpuidle can make SoC enter deepest mode like vmin (if all other conditions like other subsystem sleeping and votes on xo clock removed, etc met).

Thanks,
Maulik