tree 76dd136c6248c7bfffbf6663951e9e6b38238f20
parent 7310ece86ad7da027f85a37a0638164118a5d12f
author Maxim Levitsky <maximlevitsky@gmail.com> 1281488501 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1281542343 -0700

mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume

If you don't use CONFIG_MMC_UNSAFE_RESUME, as soon as you attempt to
suspend, the card will be removed, therefore this patch doesn't change the
behavior of this option.

However the removal will be done by pm notifier, which runs while
userspace is still not frozen and thus can freely use del_gendisk, without
the risk of deadlock which would happen otherwise.

Card detect workqueue is now disabled while userspace is frozen, Therefore
if you do use CONFIG_MMC_UNSAFE_RESUME, and remove the card during
suspend, the removal will be detected as soon as userspace is unfrozen,
again at the moment it is safe to call del_gendisk.

Tested with and without CONFIG_MMC_UNSAFE_RESUME with suspend and hibernate.

[akpm@linux-foundation.org: clean up function prototype]
[akpm@linux-foundation.org: fix CONFIG_PM-n linkage, small cleanups]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>