Re: [PATCH] usb_storage: make usb-stor-scan task non-freezable

From: Alan Stern
Date: Mon Jul 18 2011 - 17:12:39 EST

On Mon, 18 Jul 2011, Seth Forshee wrote:

> The following patch is in response to a consistently reproducible
> failure to freeze tasks prior to restoring a hibernation image on a
> Toshiba NB505 netbook. This machine has a built-in USB card reader.
> Since the usb-stor-scan task is freezable but the code in
> quiesce_and_remove_host() that waits for scanning to complete is not,
> khubd can fail to freeze when processing the disconnect for the card
> reader.

What card-reader disconnect?

> It seems that both should either be freezable or not freezable. Since
> there doesn't currently seem to be any freezable way to wait on a
> completion, I started with the simpler approach of making usb-stor-scan
> non-freezable. If it would be preferable to make both freezable I can
> take that approach instead.

I'm not sure what the best approach is. usb-stor-scan has to be
freezable, because the scanning code registers new child device
structures, which isn't allowed during suspend or hibernation.

Alan Stern

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at