linux-kernel - Re: [PATCH 3/3] clk: qcom: gcc-sc7280: Update the .pwrsts for usb gdsc

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: <4490d181-7bf2-791c-1778-1102e9adbc25@quicinc.com>
Date:   Thu, 15 Sep 2022 12:55:58 +0530
From:   Rajendra Nayak <quic_rjendra@...cinc.com>
To:     Matthias Kaehlcke <mka@...omium.org>,
        Johan Hovold <johan@...nel.org>
CC:     <andersson@...nel.org>, <agross@...nel.org>,
        <konrad.dybcio@...ainline.org>, <mturquette@...libre.com>,
        <sboyd@...nel.org>, <johan+linaro@...nel.org>,
        <quic_kriskura@...cinc.com>, <dianders@...omium.org>,
        <linux-clk@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] clk: qcom: gcc-sc7280: Update the .pwrsts for usb
 gdsc



On 9/15/2022 2:53 AM, Matthias Kaehlcke wrote:
> On Wed, Sep 14, 2022 at 09:12:36AM +0200, Johan Hovold wrote:
>> On Thu, Sep 01, 2022 at 09:04:55AM -0700, Matthias Kaehlcke wrote:
>>> On Thu, Sep 01, 2022 at 03:47:56PM +0530, Rajendra Nayak wrote:
>>>> USB on sc7280 cannot support wakeups from low power states
>>>> if the GDSC is turned OFF. Update the .pwrsts for usb GDSC so it
>>>> only transitions to RET in low power.
>>>>
>>>> Signed-off-by: Rajendra Nayak <quic_rjendra@...cinc.com>
>>>
>>> Reviewed-by: Matthias Kaehlcke <mka@...omium.org>
>>> Tested-by: Matthias Kaehlcke <mka@...omium.org>
>>
>> Did you confirm that you actually hit the retention state?
> 
> No, how would I do that?
> 
>> IIUC, this series is equivalent to using ALWAYS_ON unless CX is actually
>> powered off during suspend.
> 
> The count in /sys/kernel/debug/qcom_stats/cxsd increses with each suspend,
> however it also does that with the GDSC configured as ALWAYS_ON and with
> Rajendra's "arm64: dts: qcom: sc7280: Add required-opps for USB" [1], so

hmm, that's really not expected. With my above patch and with the GDSC as
ALWAYS_ON there is a cx vote in suspend preventing cxsd so the counter
should not go up.

> I guess that isn't the correct signal.
> 
> https://patchwork.kernel.org/project/linux-arm-msm/patch/20220914053017.23617-1-quic_rjendra@quicinc.com/