Patchwork [Lucid] pull-request: mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume

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Submitter Lee Jones
Date Sept. 3, 2010, 12:13 p.m.
Message ID <4C80E67F.5030601@canonical.com>
Download mbox | patch
Permalink /patch/63675/
State Accepted
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Comments

Lee Jones - Sept. 3, 2010, 12:13 p.m.
This patch fixes: 

BugLink: http://bugs.launchpad.net/bugs/477106

The following changes since commit 5470af5fd104192214b496a2736fd26200f4650d:
  Steve Conklin (1):
        UBUNTU: [Config] updateconfigs

are available in the git repository at:

  git://kernel.ubuntu.com/lag/ubuntu-lucid.git lp477106

Lee Jones (1):
      mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume

 drivers/mmc/core/core.c  |   87 ++++++++++++++++++++++++++++++++--------------
 drivers/mmc/core/host.c  |    5 +++
 include/linux/mmc/host.h |    6 +++
 include/linux/mmc/pm.h   |   30 ++++++++++++++++
 4 files changed, 102 insertions(+), 26 deletions(-)
 create mode 100644 include/linux/mmc/pm.h

------------------------------------------------------------------------

commit f8a01342978bcf0749b4ca27268deb47d3559261
Author: Lee Jones <lee.jones@canonical.com>
Date:   Fri Sep 3 12:42:15 2010 +0100

    mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
    
    Based on a patch-set originally written by Maxim Levitsky.
    
    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>
    
    [Backported to Ubuntu-2.6.32-25.43 by Lee Jones]
    Signed-off-by: Lee Jones <lee.jones@canonical.com>
    
    BugLink: http://bugs.launchpad.net/bugs/477106
Stefan Bader - Sept. 3, 2010, 12:48 p.m.
There are several places that do not really feel like related to the issue at hand.

On 09/03/2010 02:13 PM, Lee Jones wrote:
> This patch fixes: 
> 
> BugLink: http://bugs.launchpad.net/bugs/477106
> 
> The following changes since commit 5470af5fd104192214b496a2736fd26200f4650d:
>   Steve Conklin (1):
>         UBUNTU: [Config] updateconfigs
> 
> are available in the git repository at:
> 
>   git://kernel.ubuntu.com/lag/ubuntu-lucid.git lp477106
> 
> Lee Jones (1):
>       mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
> 
>  drivers/mmc/core/core.c  |   87 ++++++++++++++++++++++++++++++++--------------
>  drivers/mmc/core/host.c  |    5 +++
>  include/linux/mmc/host.h |    6 +++
>  include/linux/mmc/pm.h   |   30 ++++++++++++++++
>  4 files changed, 102 insertions(+), 26 deletions(-)
>  create mode 100644 include/linux/mmc/pm.h
> 
> ------------------------------------------------------------------------
> 
> commit f8a01342978bcf0749b4ca27268deb47d3559261
> Author: Lee Jones <lee.jones@canonical.com>
> Date:   Fri Sep 3 12:42:15 2010 +0100
> 
>     mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
>     
>     Based on a patch-set originally written by Maxim Levitsky.
>     
>     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>
>     
>     [Backported to Ubuntu-2.6.32-25.43 by Lee Jones]
>     Signed-off-by: Lee Jones <lee.jones@canonical.com>
>     
>     BugLink: http://bugs.launchpad.net/bugs/477106
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 30acd52..2479abe 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -106,8 +106,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>                 cmd->error = 0;
>                 host->ops->request(host, mrq);
>         } else {
> +#ifdef CONFIG_LEDS_TRIGGERS
>                 led_trigger_event(host->led, LED_OFF);
> -
> +#endif

These #ifdefs maybe beneficial but it feels like those would address some other
issue...

>                 pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
>                         mmc_hostname(host), cmd->opcode, err,
>                         cmd->resp[0], cmd->resp[1],
> @@ -163,7 +164,9 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
>  
>         WARN_ON(!host->claimed);
>  
> +#ifdef CONFIG_LEDS_TRIGGERS
>         led_trigger_event(host->led, LED_FULL);
> +#endif
> 
>         mrq->cmd->error = 0;
>         mrq->cmd->mrq = mrq;
> @@ -1057,6 +1060,17 @@ 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);
>  
> @@ -1263,18 +1277,6 @@ int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
>         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);
>  
> @@ -1304,28 +1306,61 @@ int mmc_resume_host(struct mmc_host *host)
>                         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);
> +               host->pm_flags = 0;

The line above seems to be the only reason you pulled in the new header file.
But then this variable is not used at all and maybe it would be better just to
drop that from the backport.

> +               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)
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index a268d12..0efe631 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -16,6 +16,8 @@
>  #include <linux/idr.h>
>  #include <linux/pagemap.h>
>  #include <linux/leds.h>
> +#include <linux/slab.h>
> +#include <linux/suspend.h>
>  
>  #include <linux/mmc/host.h>
>  
> @@ -84,6 +86,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
>         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 +135,7 @@ int mmc_add_host(struct mmc_host *host)
>  #endif
>  
>         mmc_start_host(host);
> +       register_pm_notifier(&host->pm_notify);
>  
>         return 0;
>  }
> @@ -148,6 +152,7 @@ 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
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index eaf3636..c43bc21 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -14,6 +14,7 @@
>  #include <linux/sched.h>
>  
>  #include <linux/mmc/core.h>
> +#include <linux/mmc/pm.h>

see above.

>  
>  struct mmc_ios {
>         unsigned int    clock;                  /* clock rate */
> @@ -120,6 +121,7 @@ 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 +179,7 @@ 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 */
> @@ -197,6 +200,8 @@ struct mmc_host {
>         struct task_struct      *sdio_irq_thread;
>         atomic_t                sdio_irq_thread_abort;
>  
> +       mmc_pm_flag_t           pm_flags;       /* requested pm features */
> +

see above.

>  #ifdef CONFIG_LEDS_TRIGGERS
>         struct led_trigger      *led;           /* activity led */
>  #endif
> @@ -249,6 +254,7 @@ int mmc_card_can_sleep(struct mmc_host *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)

This whole include file does not seem to be really required.

> diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
> new file mode 100644
> index 0000000..d37aac4
> --- /dev/null
> +++ b/include/linux/mmc/pm.h
> @@ -0,0 +1,30 @@
> +/*
> + * linux/include/linux/mmc/pm.h
> + *
> + * Author:     Nicolas Pitre
> + * Copyright:  (C) 2009 Marvell Technology Group Ltd.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef LINUX_MMC_PM_H
> +#define LINUX_MMC_PM_H
> +
> +/*
> + * These flags are used to describe power management features that
> + * some cards (typically SDIO cards) might wish to benefit from when
> + * the host system is being suspended.  There are several layers of
> + * abstractions involved, from the host controller driver, to the MMC core
> + * code, to the SDIO core code, to finally get to the actual SDIO function
> + * driver.  This file is therefore used for common definitions shared across
> + * all those layers.
> + */
> +
> +typedef unsigned int mmc_pm_flag_t;
> +
> +#define MMC_PM_KEEP_POWER      (1 << 0)        /* preserve card power during suspend */
> +#define MMC_PM_WAKE_SDIO_IRQ   (1 << 1)        /* wake up host system on SDIO IRQ assertion */
> +
> +#endif
>
Lee Jones - Sept. 3, 2010, 2:40 p.m.
On 03/09/10 13:48, Stefan Bader wrote:
> There are several places that do not really feel like related to the issue at hand.
> 
> On 09/03/2010 02:13 PM, Lee Jones wrote:
>> This patch fixes: 
>>
>> BugLink: http://bugs.launchpad.net/bugs/477106
>>
>> The following changes since commit 5470af5fd104192214b496a2736fd26200f4650d:
>>   Steve Conklin (1):
>>         UBUNTU: [Config] updateconfigs
>>
>> are available in the git repository at:
>>
>>   git://kernel.ubuntu.com/lag/ubuntu-lucid.git lp477106
>>
>> Lee Jones (1):
>>       mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
>>
>>  drivers/mmc/core/core.c  |   87 ++++++++++++++++++++++++++++++++--------------
>>  drivers/mmc/core/host.c  |    5 +++
>>  include/linux/mmc/host.h |    6 +++
>>  include/linux/mmc/pm.h   |   30 ++++++++++++++++
>>  4 files changed, 102 insertions(+), 26 deletions(-)
>>  create mode 100644 include/linux/mmc/pm.h
>>
>> ------------------------------------------------------------------------
>>
>> commit f8a01342978bcf0749b4ca27268deb47d3559261
>> Author: Lee Jones <lee.jones@canonical.com>
>> Date:   Fri Sep 3 12:42:15 2010 +0100
>>
>>     mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
>>     
>>     Based on a patch-set originally written by Maxim Levitsky.
>>     
>>     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>
>>     
>>     [Backported to Ubuntu-2.6.32-25.43 by Lee Jones]
>>     Signed-off-by: Lee Jones <lee.jones@canonical.com>
>>     
>>     BugLink: http://bugs.launchpad.net/bugs/477106
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index 30acd52..2479abe 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -106,8 +106,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>>                 cmd->error = 0;
>>                 host->ops->request(host, mrq);
>>         } else {
>> +#ifdef CONFIG_LEDS_TRIGGERS
>>                 led_trigger_event(host->led, LED_OFF);
>> -
>> +#endif
> 
> These #ifdefs maybe beneficial but it feels like those would address some other
> issue...

In include/linux/mmc/host.h these lines appear:

#ifdef CONFIG_LEDS_TRIGGERS
	struct led_trigger	*led;		/* activity led */
#endif

It seems silly to protect the declaration and not the use of the variable. 

>>                 pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
>>                         mmc_hostname(host), cmd->opcode, err,
>>                         cmd->resp[0], cmd->resp[1],
>> @@ -163,7 +164,9 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
>>  
>>         WARN_ON(!host->claimed);
>>  
>> +#ifdef CONFIG_LEDS_TRIGGERS
>>         led_trigger_event(host->led, LED_FULL);
>> +#endif
>>
>>         mrq->cmd->error = 0;
>>         mrq->cmd->mrq = mrq;
>> @@ -1057,6 +1060,17 @@ 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);
>>  
>> @@ -1263,18 +1277,6 @@ int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
>>         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);
>>  
>> @@ -1304,28 +1306,61 @@ int mmc_resume_host(struct mmc_host *host)
>>                         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);
>> +               host->pm_flags = 0;
> 
> The line above seems to be the only reason you pulled in the new header file.
> But then this variable is not used at all and maybe it would be better just to
> drop that from the backport.

I am going to redo the pull-request.

The new pull-request will contain bring this patch-set more in line with the original code.

Although this will mean more code rather than less, it will be semantically closer to the most up-to-date code.

> 
>> +               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)
>> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
>> index a268d12..0efe631 100644
>> --- a/drivers/mmc/core/host.c
>> +++ b/drivers/mmc/core/host.c
>> @@ -16,6 +16,8 @@
>>  #include <linux/idr.h>
>>  #include <linux/pagemap.h>
>>  #include <linux/leds.h>
>> +#include <linux/slab.h>
>> +#include <linux/suspend.h>
>>  
>>  #include <linux/mmc/host.h>
>>  
>> @@ -84,6 +86,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
>>         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 +135,7 @@ int mmc_add_host(struct mmc_host *host)
>>  #endif
>>  
>>         mmc_start_host(host);
>> +       register_pm_notifier(&host->pm_notify);
>>  
>>         return 0;
>>  }
>> @@ -148,6 +152,7 @@ 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
>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>> index eaf3636..c43bc21 100644
>> --- a/include/linux/mmc/host.h
>> +++ b/include/linux/mmc/host.h
>> @@ -14,6 +14,7 @@
>>  #include <linux/sched.h>
>>  
>>  #include <linux/mmc/core.h>
>> +#include <linux/mmc/pm.h>
> 
> see above.
> 
>>  
>>  struct mmc_ios {
>>         unsigned int    clock;                  /* clock rate */
>> @@ -120,6 +121,7 @@ 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 +179,7 @@ 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 */
>> @@ -197,6 +200,8 @@ struct mmc_host {
>>         struct task_struct      *sdio_irq_thread;
>>         atomic_t                sdio_irq_thread_abort;
>>  
>> +       mmc_pm_flag_t           pm_flags;       /* requested pm features */
>> +
> 
> see above.
> 
>>  #ifdef CONFIG_LEDS_TRIGGERS
>>         struct led_trigger      *led;           /* activity led */
>>  #endif
>> @@ -249,6 +254,7 @@ int mmc_card_can_sleep(struct mmc_host *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)
> 
> This whole include file does not seem to be really required.
> 
>> diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
>> new file mode 100644
>> index 0000000..d37aac4
>> --- /dev/null
>> +++ b/include/linux/mmc/pm.h
>> @@ -0,0 +1,30 @@
>> +/*
>> + * linux/include/linux/mmc/pm.h
>> + *
>> + * Author:     Nicolas Pitre
>> + * Copyright:  (C) 2009 Marvell Technology Group Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#ifndef LINUX_MMC_PM_H
>> +#define LINUX_MMC_PM_H
>> +
>> +/*
>> + * These flags are used to describe power management features that
>> + * some cards (typically SDIO cards) might wish to benefit from when
>> + * the host system is being suspended.  There are several layers of
>> + * abstractions involved, from the host controller driver, to the MMC core
>> + * code, to the SDIO core code, to finally get to the actual SDIO function
>> + * driver.  This file is therefore used for common definitions shared across
>> + * all those layers.
>> + */
>> +
>> +typedef unsigned int mmc_pm_flag_t;
>> +
>> +#define MMC_PM_KEEP_POWER      (1 << 0)        /* preserve card power during suspend */
>> +#define MMC_PM_WAKE_SDIO_IRQ   (1 << 1)        /* wake up host system on SDIO IRQ assertion */
>> +
>> +#endif
>>
>

Patch

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 30acd52..2479abe 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -106,8 +106,9 @@  void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
                cmd->error = 0;
                host->ops->request(host, mrq);
        } else {
+#ifdef CONFIG_LEDS_TRIGGERS
                led_trigger_event(host->led, LED_OFF);
-
+#endif
                pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
                        mmc_hostname(host), cmd->opcode, err,
                        cmd->resp[0], cmd->resp[1],
@@ -163,7 +164,9 @@  mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 
        WARN_ON(!host->claimed);
 
+#ifdef CONFIG_LEDS_TRIGGERS
        led_trigger_event(host->led, LED_FULL);
+#endif

        mrq->cmd->error = 0;
        mrq->cmd->mrq = mrq;
@@ -1057,6 +1060,17 @@  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);
 
@@ -1263,18 +1277,6 @@  int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
        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);
 
@@ -1304,28 +1306,61 @@  int mmc_resume_host(struct mmc_host *host)
                        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);
+               host->pm_flags = 0;
+               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)
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index a268d12..0efe631 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -16,6 +16,8 @@ 
 #include <linux/idr.h>
 #include <linux/pagemap.h>
 #include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
 
 #include <linux/mmc/host.h>
 
@@ -84,6 +86,7 @@  struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
        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 +135,7 @@  int mmc_add_host(struct mmc_host *host)
 #endif
 
        mmc_start_host(host);
+       register_pm_notifier(&host->pm_notify);
 
        return 0;
 }
@@ -148,6 +152,7 @@  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
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index eaf3636..c43bc21 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -14,6 +14,7 @@ 
 #include <linux/sched.h>
 
 #include <linux/mmc/core.h>
+#include <linux/mmc/pm.h>
 
 struct mmc_ios {
        unsigned int    clock;                  /* clock rate */
@@ -120,6 +121,7 @@  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 +179,7 @@  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 */
@@ -197,6 +200,8 @@  struct mmc_host {
        struct task_struct      *sdio_irq_thread;
        atomic_t                sdio_irq_thread_abort;
 
+       mmc_pm_flag_t           pm_flags;       /* requested pm features */
+
 #ifdef CONFIG_LEDS_TRIGGERS
        struct led_trigger      *led;           /* activity led */
 #endif
@@ -249,6 +254,7 @@  int mmc_card_can_sleep(struct mmc_host *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)
diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
new file mode 100644
index 0000000..d37aac4
--- /dev/null
+++ b/include/linux/mmc/pm.h
@@ -0,0 +1,30 @@ 
+/*
+ * linux/include/linux/mmc/pm.h
+ *
+ * Author:     Nicolas Pitre
+ * Copyright:  (C) 2009 Marvell Technology Group Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef LINUX_MMC_PM_H
+#define LINUX_MMC_PM_H
+
+/*
+ * These flags are used to describe power management features that
+ * some cards (typically SDIO cards) might wish to benefit from when
+ * the host system is being suspended.  There are several layers of
+ * abstractions involved, from the host controller driver, to the MMC core
+ * code, to the SDIO core code, to finally get to the actual SDIO function
+ * driver.  This file is therefore used for common definitions shared across
+ * all those layers.
+ */
+
+typedef unsigned int mmc_pm_flag_t;
+
+#define MMC_PM_KEEP_POWER      (1 << 0)        /* preserve card power during suspend */
+#define MMC_PM_WAKE_SDIO_IRQ   (1 << 1)        /* wake up host system on SDIO IRQ assertion */
+
+#endif