Re: [Bug 10030] Suspend doesn't work when SD card is inserted

[Pierre Ossman]

On Wed, 20 Feb 2008 11:42:56 -0500 (EST)
Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:

> > 
> > ------- Comment #14 from rjw@xxxxxxx  2008-02-19 15:23 -------
> > Thanks a lot for the debugging work!
> > 
> > First, the patch triggers, which means that the problem discovered by Alan is
> > troubling us.  [Alan, do you have an idea how to fix that cleanly?]
> 
> I suggest we ask the maintainer for the MMC subsystem.
> 
> Pierre, you can find the details in the bugzilla entry.  Briefly,
> there's a pathway in the MMC core suspend routine (if the driver
> doesn't implement a resume hook) which could lead to the host being
> removed during a system suspend.  This is an illegal operation and it
> will deadlock.
> 
> Do you have a suggestion for a way to fix it?
> 

Not really. But you have some things confused. What it checks is if the mmc bus handler (not a proper driver model, just a way of separating the MMC, SD and SDIO stuff) has a resume function. And if it doesn't, it removes the card (since it cannot revive it at resume).

So the only thing I can think of is to delay the removal until the resume routine, if that is safer.

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  PulseAudio, core developer          http://pulseaudio.org
  rdesktop, core developer          http://www.rdesktop.org
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