linux-kernel - Re: [PATCH 0/3] clk: qcom: smd-rpm: Report enable state to framework

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: <20211111093926.GL7231@dragon>
Date:   Thu, 11 Nov 2021 17:39:27 +0800
From:   Shawn Guo <shawn.guo@...aro.org>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     Stephan Gerhold <stephan@...hold.net>,
        Stephen Boyd <sboyd@...nel.org>,
        Loic Poulain <loic.poulain@...aro.org>,
        linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/3] clk: qcom: smd-rpm: Report enable state to framework

On Wed, Nov 10, 2021 at 05:48:10AM -0800, Bjorn Andersson wrote:
> > IMHO, properly reporting enable state to framework is definitely the
> > right thing to do, and should have been done from day one.
> > 
> 
> I always thought is_enabled() should reflect the hardware state - in
> particular for clk_summary. The particular concern being that by
> initializing the is_enabled() state to either true or false, we're
> making an assumption about the hardware state. And if something where to
> do if (enabled) disable (or if (disabled) enable), we might skip a
> critical operation just because we tricked the logic.

That's probably why clk_smd_rpm_handoff() is called.  As there is no way
to query RPM for resource state, we send enable request for all RPM
clocks to get hardware and software state in sync.

> So, do you need it for anything other than clk_disable_unused()?

Not critical, but I need it for debugfs clk_summary as well.

Shawn