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>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f65913c..513ff03 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -124,6 +124,7 @@
unsigned int f_min;
unsigned int f_max;
u32 ocr_avail;
+ struct notifier_block pm_notify;
#define MMC_VDD_165_195 0x00000080 /* VDD voltage 1.65 - 1.95 */
#define MMC_VDD_20_21 0x00000100 /* VDD voltage 2.0 ~ 2.1 */
@@ -183,6 +184,7 @@
/* Only used with MMC_CAP_DISABLE */
int enabled; /* host is enabled */
+ int rescan_disable; /* disable card detection */
int nesting_cnt; /* "enable" nesting count */
int en_dis_recurs; /* detect recursion */
unsigned int disable_delay; /* disable delay in msecs */
@@ -257,6 +259,7 @@
int mmc_host_enable(struct mmc_host *host);
int mmc_host_disable(struct mmc_host *host);
int mmc_host_lazy_disable(struct mmc_host *host);
+int mmc_pm_notify(struct notifier_block *notify_block, unsigned long, void *);
static inline void mmc_set_disable_delay(struct mmc_host *host,
unsigned int disable_delay)