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From:   Kalesh Singh <kaleshsingh@google.com>
Date:   Wed, 29 Jun 2022 21:25:32 -0700
Message-ID: <CAC_TJvcNOx1C5csdkMCAPVmX4gLcRWkxKO8Vm=isgjgM-MowwA@mail.gmail.com>
Subject: Re: [PATCH] remove CONFIG_ANDROID
To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     John Stultz <jstultz@google.com>, Christoph Hellwig <hch@lst.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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On Wed, Jun 29, 2022 at 5:30 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> Hey again,
>
> On Thu, Jun 30, 2022 at 2:24 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> > 1) Introduce a simple CONFIG_PM_CONTINUOUS_AUTOSLEEPING Kconfig thing
> >    with lots of discouraging help text.
> >
> > 2) Go with the /sys/power tunable and bikeshed the naming of that a bit
> >    to get it to something that reflects this better, and document it as
> >    being undesirable except for Android phones.
>
> One other quick thought, which I had mentioned earlier to Kalesh:
>
> 3) Make the semantics a process holding open a file descriptor, rather
>    than writing 0/1 into a file. It'd be called /sys/power/
>    userspace_autosleep_ctrl, or something, and it'd enable this behavior
>    while it's opened. And maybe down the line somebody will want to add
>    ioctls to it for a different purpose. This way it's less of a tunable
>    and more of an indication that there's a userspace app doing/controlling
>    something.
>
> This idea (3) may be a lot of added complexity for basically nothing,
> but it might fit the usage semantics concerns a bit better than (2). But
> anyway, just an idea. Any one of those three are fine with me.

Two concerns John raised:
  1) Adding new ABI we need to maintain
  2) Having unclear config options

Another idea, I think, is to add the Kconfig option as
CONFIG_SUSPEND_SKIP_RNG_RESEED? Similar to existing
CONFIG_SUSPEND_SKIP_SYNC and I think it would address those concerns.

--Kalesh

> Jason