Re: Suspend to disk with PCMCIA card plugged in with kernel 2.6.16.28

[Pavel Machek <pavel@ucw.cz>]

Hi!

> 	I have a PCMCIA card hosting a USB port. I am facing some
> problems while trying to suspend my laptop to disk . Given below are
> some of my observations:
> 
> 1. With kernel 2.6.15.4, my system does not get suspended to disk with
> the PCMCIA card plugged in. I went through the mailing list and found a
> mail thread desribing the same.
> http://lists.infradead.org/pipermail/linux-pcmcia/2006-January/003123.ht
> ml
> 
> This seems to be the breakage in resume path and not fixed in 2.6.15.4.
> So the final thing is, I have to remove my PCMCIA card before trying to
> suspend my system to disk.
> 
> 2. With the kernel 2.6.16.28, the above breakage seems to be fixed. So I
> tried suspending my system to disk with my PCMCIA card plugged in but
> without any device connected to the USB port of the PCMCIA card. This
> works fine. My system responds fine, suspends to disk properly and
> resumes back as well.
> 
> 3. Now I try a step ahead and tried suspending the system to disk with
> the PCMCIA card plugged in as well as a USB speaker/webcam connected to
> the USB port of PCMCIA card. This also works fine. My system is
> suspended and resumed properly.
> 
> 4. Now again going a step ahead. I plugged in my PCMCIA card, then I
> connected a USB speaker to the USB port of the card and started playing
> a song. Now I suspended the system to disk while the transfer was in
> progress( song was being played). But this time my system hangs. This
> happens with other isochronous devices like webcam and bulk device like
> USB key as well. So suspend to disk fails if any USB transfer is in
> progress ( through the USB port of my PCMCIA card).
> 
> I tried debugging the problem and used kdb to find out the reason. For
> all the devices I found out the following thing :
> 
> The system hangs in following path: usb_disconnect -->
> usb_disable_device --> put_device.
> After put_device the system hangs. As I was in kdb mode I could not save
> the stack trace.
> 
> Is it a known kernel problem with 2.6.16.28 ? Please suggest.

Reproduce it with 2.6.18, then it is bugzilla time, or post to
linux-usb mailing list.
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html