On Monday, July 06, 2015 01:06:45 PM Pavel Machek wrote:

On Mon 2015-07-06 01:28:20, Rafael J. Wysocki wrote:

quoted

On Saturday, July 04, 2015 10:19:55 AM Alan Stern wrote:

quoted

On Sat, 4 Jul 2015, Rafael J. Wysocki wrote:

quoted

The only argument against dropping sys_sync() from the suspend code path
I've seen in this thread that I entirely agree with is that it may lead to
regressions, because we've done it practically forever and it may hide latent
bugs somewhere in block drivers etc.  Dropping it, though, is the only way
to see those bugs, if any, and if we want to ever fix them, we need to see
them.  That's why I think that it may be a good idea to allow people to
drop it if they are willing to accept some extra risk (via the kernel
command line, for example).

I'd be perfectly happy to have the sync selectable at runtime, one way 
or another.  The three most reasonable options seem to be:

	kernel command line

	sysfs file

	sysctl setting

The command line is less flexible (it can't be changed after booting).  
Either of the other two would be fine with me.

We'll probably use a sysfs file (possibly plus a Kconfig option to set the
boot time default).

Android people can already do sync-less s2ram using existing
interface. IMO they should just do it.

In any case, sysfs file + Kconfig is an overkill. We already have too
many Kconfig options.

I don't think we can reach a general agreement on what's the *right* approach
with respect to the sys_sync() in the suspend code path, so the only way out
of this situation I can see is to make it configurable.

There's not a single Android phone supported by mainline
kernel. I'm sure they have bigger problems than Android setting
default sysfs values...

But perhaps we'd like to change that?

Thanks,
Rafael