Re: [PATCH v13 1/9] scsi: sr: support runtime pm

[Alan Stern <stern@rowland.harvard.edu>]

On Sat, 19 Jan 2013, Aaron Lu wrote:

> > What happens if you're not running a desktop graphical environment, so
> > gvfs doesn't mount the disc?  Basically, I'm worried that the drive may
> > remain suspended after sr_open() returns.
> 
> Tried on my notebook with a normal ODD, using mplayer under console
> mode, no GUI environment running, works fine.
> 
> The usage count will be incremented by the app, and get decreased
> only when it exits. So the ODD will not be in runtime suspended state
> when the app is running.

You missed my point.  What happens when sr_open() gets called?  It 
doesn't try to resume the device.  Will we run into trouble then?

> > What happens if you use a program other than rhythmbox?  There are (or
> > used to be) programs which would issue the PLAY AUDIO command and then
> > exit.  The drive would continue playing even while the device file was
> 
> Then we indeed have a problem. But I didn't find any such app in
> Fedora's repo or by searching the internet.

http://rpm.pbone.net/index.php3/stat/4/idpl/2392183/dir/redhat_5.x/com/cdp-0.33-10.i386.rpm.html

> > closed.  Do we want to drop support for that kind of behavior?
> 
> I don't think we should drop such support.
> And the safest way to avoid such break is we refine the suspend
> condition for ODD, and using what ZPODD defined condition isn't that
> bad to me:
> - for tray type, no media inside and tray close;
> - for slot type, no media inside.
> While whether tray is closed or not may not be that important, but at
> least we should make sure there is no media inside.
> 
> Thoughts?

That sounds reasonable to me, at least as a first step.  If people want 
their CD drive to suspend, they can eject the disc.

Alan Stern