Subject: Re: Call for testers: power management branch
To: Steven M. Bellovin <smb@cs.columbia.edu>
From: Jared D. McNeill <jmcneill@invisible.ca>
List: current-users
Date: 08/04/2007 11:59:20
On Sat, 4 Aug 2007, Steven M. Bellovin wrote:
> I tried your new kernel on a Thinkpad T42 (and I thank you for doing
> this work!). Results were mixed but encouraging.  Unfortunately, I
> didn't run dmidecode because this note was on the laptop I was testing,
> so I didn't see that I was supposed to...

dmidecode is always handy to have :)

> Anyway -- suspend/resume itself worked.  It did before these changes,
> too.  The disk and CD worked after resume; I was able to keep a CD
> mounted across a suspend/resume.

Very cool.

> USB worked after a suspend/resume; it had not worked after an ACPI
> resume before.  If, however, I had a flash disk mounted at suspend
> time, it didn't work after resume unless I unmounted and mounted it
> again.  A USB keyboard worked perfectly across a suspend/resume.
> Plugging in my iPod indicates that the USB slots are powered down
> properly.

Interesting, I'll have to look into that (missing power handler in umass 
most likely).

> ath0 works after suspend/resume (well, to the extent that it works at
> all on 4.99.26, per another thread....).  I don't recall what it did
> before.

Good news :)

> wm0 does *not* work after resume.  Here's some relevant dmesg output:
[..]
> wm0: WARNING: powerhook_establish is deprecated; please see devpm(4)

Ah, this powerhook simply needs to be converted to the new API. I can send 
a patch for you to try at some point later on in the day.

> Audio was mixed.  After a resume, *something* was working, in that
> echoing ^g to the console produced a beep.  However, mpg123 did not
> work afterwards.  It's possible that some relevant setting wasn't
> restored; however, outputs.master's value (which I have to set to
> 255,255 at boot time) was restored properly.  Here is the only dmesg
> about it:
[...]
> auich0: WARNING: powerhook_establish is deprecated; please see devpm(4)
> auich0: WARNING: power management not supported

See above.

> A CF disk in a cbb slot worked properly after resume, even if it was
> mounted at suspend time.  The blinkenlights on an EVDO card (which
> shows up as umodem0 attached to ohci attached to cbb) indicate that the
> slot was not powered down by a suspend.  (No surprise, since the driver
> for cbb warns that it doesn't support powerhooks.)  Leaving the EVDO
> card in across suspend/resume had mixed results.  Once, it worked after
> resume (though it took a few seconds); once, it didn't, and I couldn't
> even get out of cu.

That powerhook should be converted as well..

> The VGA display was cleared by the resume process, a minor nuisance.
>
> Sometimes -- I'm not certain how often -- I got two 'resume' messages
> on the console.  I'm not sure if that's real or if it's some artifact
> of syslogd not running.  (All tests were done in single-user mode with
> the disk mounted read-only.)

I see this as well -- I simply need to ask vga(4) to redraw the screen in 
its resume path.

Thanks for the input! Looks like we're making good progress :-)

Cheers,
Jared