On Wed, Jun 29, 2022 at 6:45 PM Christoph Hellwig [off-list ref] wrote:

On Wed, Jun 29, 2022 at 06:38:09PM +0200, Jason A. Donenfeld wrote:

quoted

On the technical topic, an Android developer friend following this
thread just pointed out to me that Android doesn't use PM_AUTOSLEEP and
just has userspace causing suspend frequently. So by his rough
estimation your patch actually *will* break Android devices. Zoinks.
Maybe he's right, maybe he's not -- I don't know -- but you should
probably look into this if you want this patch to land without breakage.

And it will also "break" anyone else doing frequent suspends from
userspace, as that behavior is still in no way related to
CONFIG_ANDROID.

I don't know of any actual systems that do this for which
CONFIG_PM_AUTOSLEEP and CONFIG_ANDROID are both disabled. At least
that was what I concluded back in 2017-2018 when I looked at this
last. And so far, no other-handset-users have reported bugs.

But of course I agree that this all could be improved with something
more granular somehow, somewhere. I don't really have any developed
opinions on what that looks like or what form that should take.

However, the thing I do have a strong opinion on is that the change
you're proposing shouldn't break things. And that's what your patch
currently might do (or not!).

In other words, instead of making the current situation worse,
justified by your observation that in theory the current mechanism is
imperfect, please make the situation better. Or conclude that it
doesn't make the situation worse, and put the reason why inside your
commit message, which is the first thing I asked.

Jason