Patch "mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume" has been added to the 2.6.32-longterm tree

Patch "mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume" has been added to the 2.6.32-longterm tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 2.6.32-longterm tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary

The filename of the patch is:
     mmc-fix-all-hangs-related-to-mmc-sd-card-insert-remo.patch
and it can be found in the queue-2.6.32 subdirectory.

If you, or anyone else, feels it should not be added to the 2.6.32 longterm tree,
please let <stable@kernel.org> know about it.


>From 849d6563ac4395a9890e6a1d10573c79237d4e8f Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky@gmail.com>
Date: Tue, 10 Aug 2010 18:01:41 -0700
Subject: mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume

From: Maxim Levitsky <maximlevitsky@gmail.com>

commit 4c2ef25fe0b847d2ae818f74758ddb0be1c27d8e upstream.

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>
[bwh: Adjust for 2.6.32]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/mmc/core/core.c  |   81 ++++++++++++++++++++++++++++++++---------------
 drivers/mmc/core/host.c  |    4 ++
 include/linux/mmc/host.h |    3 +
 3 files changed, 63 insertions(+), 25 deletions(-)

--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1041,6 +1041,17 @@ void mmc_rescan(struct work_struct *work
 		container_of(work, struct mmc_host, detect.work);
 	u32 ocr;
 	int err;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	if (host->rescan_disable) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		return;
+	}
+
+	spin_unlock_irqrestore(&host->lock, flags);
+
 
 	mmc_bus_get(host);
 
@@ -1247,18 +1258,6 @@ int mmc_suspend_host(struct mmc_host *ho
 	if (host->bus_ops && !host->bus_dead) {
 		if (host->bus_ops->suspend)
 			err = host->bus_ops->suspend(host);
-		if (err == -ENOSYS || !host->bus_ops->resume) {
-			/*
-			 * We simply "remove" the card in this case.
-			 * It will be redetected on resume.
-			 */
-			if (host->bus_ops->remove)
-				host->bus_ops->remove(host);
-			mmc_claim_host(host);
-			mmc_detach_bus(host);
-			mmc_release_host(host);
-			err = 0;
-		}
 	}
 	mmc_bus_put(host);
 
@@ -1288,28 +1287,60 @@ int mmc_resume_host(struct mmc_host *hos
 			printk(KERN_WARNING "%s: error %d during resume "
 					    "(card was removed?)\n",
 					    mmc_hostname(host), err);
-			if (host->bus_ops->remove)
-				host->bus_ops->remove(host);
-			mmc_claim_host(host);
-			mmc_detach_bus(host);
-			mmc_release_host(host);
-			/* no need to bother upper layers */
 			err = 0;
 		}
 	}
 	mmc_bus_put(host);
 
-	/*
-	 * We add a slight delay here so that resume can progress
-	 * in parallel.
-	 */
-	mmc_detect_change(host, 1);
-
 	return err;
 }
-
 EXPORT_SYMBOL(mmc_resume_host);
 
+/* Do the card removal on suspend if card is assumed removeable
+ * Do that in pm notifier while userspace isn't yet frozen, so we will be able
+   to sync the card.
+*/
+int mmc_pm_notify(struct notifier_block *notify_block,
+					unsigned long mode, void *unused)
+{
+	struct mmc_host *host = container_of(
+		notify_block, struct mmc_host, pm_notify);
+	unsigned long flags;
+
+
+	switch (mode) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_SUSPEND_PREPARE:
+
+		spin_lock_irqsave(&host->lock, flags);
+		host->rescan_disable = 1;
+		spin_unlock_irqrestore(&host->lock, flags);
+		cancel_delayed_work_sync(&host->detect);
+
+		if (!host->bus_ops || host->bus_ops->suspend)
+			break;
+
+		mmc_claim_host(host);
+
+		if (host->bus_ops->remove)
+			host->bus_ops->remove(host);
+
+		mmc_detach_bus(host);
+		mmc_release_host(host);
+		break;
+
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+
+		spin_lock_irqsave(&host->lock, flags);
+		host->rescan_disable = 0;
+		spin_unlock_irqrestore(&host->lock, flags);
+		mmc_detect_change(host, 0);
+
+	}
+
+	return 0;
+}
 #endif
 
 static int __init mmc_init(void)
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -16,6 +16,7 @@
 #include <linux/idr.h>
 #include <linux/pagemap.h>
 #include <linux/leds.h>
+#include <linux/suspend.h>
 
 #include <linux/mmc/host.h>
 
@@ -84,6 +85,7 @@ struct mmc_host *mmc_alloc_host(int extr
 	init_waitqueue_head(&host->wq);
 	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
 	INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
+	host->pm_notify.notifier_call = mmc_pm_notify;
 
 	/*
 	 * By default, hosts do not support SGIO or large requests.
@@ -132,6 +134,7 @@ int mmc_add_host(struct mmc_host *host)
 #endif
 
 	mmc_start_host(host);
+	register_pm_notifier(&host->pm_notify);
 
 	return 0;
 }
@@ -148,6 +151,7 @@ EXPORT_SYMBOL(mmc_add_host);
  */
 void mmc_remove_host(struct mmc_host *host)
 {
+	unregister_pm_notifier(&host->pm_notify);
 	mmc_stop_host(host);
 
 #ifdef CONFIG_DEBUG_FS
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -120,6 +120,7 @@ struct mmc_host {
 	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 */
@@ -177,6 +178,7 @@ struct mmc_host {
 
 	/* 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 */
@@ -249,6 +251,7 @@ int mmc_card_can_sleep(struct mmc_host *
 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)


Patches currently in longterm-queue-2.6.32 which might be from maximlevitsky@gmail.com are

/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/mmc-build-fix-mmc_pm_notify-is-only-available-with-c.patch
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/mmc-fix-all-hangs-related-to-mmc-sd-card-insert-remo.patch

Re: Patch "mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume" has been added to the 2.6.32-longterm tree

[Ohad Ben-Cohen]

On Fri, May 6, 2011 at 12:54 AM,  <gregkh@suse.de> wrote:
>
> This is a note to let you know that I've just added the patch titled
>
>    mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
>
> to the 2.6.32-longterm tree

That patch introduced a suspend/resume regression, so please also add
the one that fixed it:

commit 1c8cf9c997a4a6b36e907c7ede5f048aeaab1644
Author: Ohad Ben-Cohen <ohad@wizery.com>
Date:   Wed Oct 13 09:31:56 2010 +0200

    mmc: sdio: fix SDIO suspend/resume regression

    Fix SDIO suspend/resume regression introduced by 4c2ef25fe0b "mmc: fix
    all hangs related to mmc/sd card insert/removal during suspend/resume":

      PM: Syncing filesystems ... done.
      Freezing user space processes ... (elapsed 0.01 seconds) done.
      Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
      Suspending console(s) (use no_console_suspend to debug)
      pm_op(): platform_pm_suspend+0x0/0x5c returns -38
      PM: Device pxa2xx-mci.0 failed to suspend: error -38
      PM: Some devices failed to suspend

    4c2ef25fe0b moved the card removal/insertion mechanism out of MMC's
    suspend/resume path and into pm notifiers (mmc_pm_notify), and that
    broke SDIO's expectation that mmc_suspend_host() will remove the card,
    and squash the error, in case -ENOSYS is returned from the bus suspend
    handler (mmc_sdio_suspend() in this case).

    mmc_sdio_suspend() is using this whenever at least one of the card's SDIO
    function drivers does not have suspend/resume handlers - in that case
    it is agreed to force removal of the entire card.

    This patch fixes this regression by trivially bringing back that part of
    mmc_suspend_host(), which was removed by 4c2ef25fe0b.

    Reported-and-tested-by: Sven Neumann <s.neumann@raumfeld.com>
    Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
    Cc: Maxim Levitsky <maximlevitsky@gmail.com>
    Cc: <stable@kernel.org>
    Acked-by: Nicolas Pitre <nico@fluxnic.net>
    Signed-off-by: Chris Ball <cjb@laptop.org>

Thanks,
Ohad.

Re: [stable] Patch "mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume" has been added to the 2.6.32-longterm tree

[Greg KH]

On Fri, May 06, 2011 at 09:37:46AM +0300, Ohad Ben-Cohen wrote:
> On Fri, May 6, 2011 at 12:54 AM,  <gregkh@suse.de> wrote:
> >
> > This is a note to let you know that I've just added the patch titled
> >
> >    mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
> >
> > to the 2.6.32-longterm tree
> 
> That patch introduced a suspend/resume regression, so please also add
> the one that fixed it:
> 
> commit 1c8cf9c997a4a6b36e907c7ede5f048aeaab1644
> Author: Ohad Ben-Cohen <ohad@wizery.com>
> Date:   Wed Oct 13 09:31:56 2010 +0200
> 
>     mmc: sdio: fix SDIO suspend/resume regression
> 
>     Fix SDIO suspend/resume regression introduced by 4c2ef25fe0b "mmc: fix
>     all hangs related to mmc/sd card insert/removal during suspend/resume":
> 
>       PM: Syncing filesystems ... done.
>       Freezing user space processes ... (elapsed 0.01 seconds) done.
>       Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
>       Suspending console(s) (use no_console_suspend to debug)
>       pm_op(): platform_pm_suspend+0x0/0x5c returns -38
>       PM: Device pxa2xx-mci.0 failed to suspend: error -38
>       PM: Some devices failed to suspend
> 
>     4c2ef25fe0b moved the card removal/insertion mechanism out of MMC's
>     suspend/resume path and into pm notifiers (mmc_pm_notify), and that
>     broke SDIO's expectation that mmc_suspend_host() will remove the card,
>     and squash the error, in case -ENOSYS is returned from the bus suspend
>     handler (mmc_sdio_suspend() in this case).
> 
>     mmc_sdio_suspend() is using this whenever at least one of the card's SDIO
>     function drivers does not have suspend/resume handlers - in that case
>     it is agreed to force removal of the entire card.
> 
>     This patch fixes this regression by trivially bringing back that part of
>     mmc_suspend_host(), which was removed by 4c2ef25fe0b.
> 
>     Reported-and-tested-by: Sven Neumann <s.neumann@raumfeld.com>
>     Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
>     Cc: Maxim Levitsky <maximlevitsky@gmail.com>
>     Cc: <stable@kernel.org>
>     Acked-by: Nicolas Pitre <nico@fluxnic.net>
>     Signed-off-by: Chris Ball <cjb@laptop.org>

Now queued up, thanks.

greg k-h