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

Pierre Ossman
2008-03-01T14:13:01Z

On Mon, 25 Feb 2008 15:00:51 -0500 (EST)
Alan Stern <stern@rowland.harvard.edu> wrote:

>
> Maybe a better approach would be to leave the workqueue unfreezable,
> and keep cancel_delayed_work_sync() in mmc_suspend_host(). It would
> then be necessary to add a test to verify, if there is a card attached,
> that the card is indeed suspended. After all, it's possible that the
> cancel_delayed_work_sync() ended up waiting for a job already running
> on the workqueue to register a new card! (The same would be true even
> with flush_scheduled_work.)

How would that be handled? I'd prefer a patch as I'm evidently not up to date with how to fondle the pm stuff properly. :)

>
> Also, as a bit of defensive programming, it might be a good idea to add
> a "suspended" flag to the mmc_host structure. If mmc_rescan() sees
> that the flag is set then it should return immediately. This would
> protect against host drivers that aren't careful to disable detect
> IRQs before calling mmc_suspend_host().

Indeed. I'll add that to my todo.

Rgds

--
-- Pierre Ossman

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