linux-kernel - Re: [PATCH 11/14] scsi: ufs: host: Add support for parsing OPP

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: <20230713054302.tu6fgd3meb5krsx5@vireshk-i7>
Date:   Thu, 13 Jul 2023 11:13:02 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Cc:     Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, vireshk@...nel.org,
        nm@...com, sboyd@...nel.org, myungjoo.ham@...sung.com,
        kyungmin.park@...sung.com, cw00.choi@...sung.com,
        andersson@...nel.org, konrad.dybcio@...aro.org, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        quic_asutoshd@...cinc.com, quic_cang@...cinc.com,
        quic_nitirawa@...cinc.com, quic_narepall@...cinc.com,
        quic_bhaskarv@...cinc.com, quic_richardp@...cinc.com,
        quic_nguyenb@...cinc.com, quic_ziqichen@...cinc.com,
        bmasney@...hat.com, krzysztof.kozlowski@...aro.org
Subject: Re: [PATCH 11/14] scsi: ufs: host: Add support for parsing OPP

Okay, sorry about missing one point first. I thought we are adding the
clk config callback (which neglects 0 frequencies) to a Qcom only
driver and so was okay-ish with that. But now that I realize that this
is a generic driver instead (my mistake here), I wonder if it is the
right thing to do anymore.

On 13-07-23, 10:58, Manivannan Sadhasivam wrote:
> On Thu, Jul 13, 2023 at 10:42:35AM +0530, Viresh Kumar wrote:
> > On 13-07-23, 10:35, Manivannan Sadhasivam wrote:
> > > We can settle with this custom callback for now. If there are drivers in the
> > > future trying to do the same (skipping 0 freq) then we can generalize.
> > 
> > Just for completeness, there isn't much to generalize here apart from
> > changing the DT order of clocks. Isn't it ?
> > 
> 
> Even with changing the order, driver has to know the "interesting" clocks
> beforehand. But that varies between platforms (this is a generic driver for
> ufshc platforms).
> 
> And I do not know if clocks have any dependency between them, atleast not in
> Qcom platforms. But not sure about others.

Maybe this requires some sort of callback, per-platform, which gets
you these details or the struct dev_pm_opp_config itself (so platforms
can choose the callback too, in case order is important).

> > The change require for the OPP core makes sense, I will probably just
> > push it anyway.

I tried to look at this code and I think it is doing the right thing
currently, i.e. it matches clk-count with the number of frequencies in
opp-hz, which should turn out to be the same in your case. So nothing
to change here I guess.

-- 
viresh