Re: USB APM suspend

[David Brownell <david-b@pacbell.net>]

Alan Stern wrote:
> Here's a piece from my system log, when I did "apm --suspend".  The 
> usb_device_suspend/resume messages are things I added for debugging.

That's progress ... last time I tried APM on 2.6 it failed horribly.
(This was after working fine until recently.)


> Why was this routine called twice?  (Don't be fooled by the timestamps; I 
> think the "suspend D4 --> D3" message was created during the suspend but 
> not read by syslogd until after the resume.)

That's happened for as long as I remember (2.4 also).
Still seems buglike to me, maybe 2.6 will finally squish it...

> Why doesn't usb_hcd_pci_resume() log a similar message when it is called?
> A simple oversight?

You mean, why didn't it announce its first resume?  Basically, yes.

> Why was the host controller suspended _before_ its child USB devices?  

Seems buglike to me, with the first call being wrong (before the
children were suspended) and the second being right (after).

> And why was it woken up twice?

The converse of the "suspended-twice" problem:  first call right,
second call (after children) wrong.

- Dave