linux-kernel - Re: Question about "regulator: core: Only count load for enabled consumers" in -next

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]

Date:   Mon, 26 Nov 2018 10:11:48 -0800
From:   Doug Anderson <dianders@...omium.org>
To:     Mark Brown <broonie@...nel.org>
Cc:     masneyb@...tation.org, Liam Girdwood <lgirdwood@...il.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: Question about "regulator: core: Only count load for enabled
 consumers" in -next

Hi,

On Mon, Nov 26, 2018 at 9:59 AM Mark Brown <broonie@...nel.org> wrote:
>
> On Mon, Nov 26, 2018 at 09:43:42AM -0800, Doug Anderson wrote:
>
> > NOTE: another option would be to change the regulator driver to just
> > force this rail to a high power mode and never let it change.  That's
> > what we're doing on a SDM845-based board.  When the regulator is off
> > the mode doesn't matter and as per the above argument we always want
> > it in high power mode when it's on.
>
> You should never need to modify the driver for this, the regulator
> framework will only change things if it's been given permission to do
> so - simply don't specify a regulator-allowed-modes property and the
> mode will be left alone (we should probably still use -initial-mode if
> it's specified but I'd need to check if we actually do).

Ah, right, there's nothing actually in rpmh and it's all in the core.
So it's just removing 'regulator-allowed-modes' and adding a
'regulator-initial-mode' property.

...hrm, but it looks like this won't just magically apply to the older
RPM driver.  For one it looks like the conversion from load to mode
happens outside of Linux (on the AOP I guess?).  rpm_reg_set_load()
just takes the load you pass it and sends it on.  It looks like you
can still force the mode but it looks like it's using a custom
attribute for that (qcom,force-mode).  I wonder if that should be
changed to use 'regulator-initial-mode'...

-Doug