[APPLIED] Re: [Maverick] pull-request: mmc: fix all hangs related to mmc/sd card insert/removal during

Leann Ogasawara leann.ogasawara at canonical.com
Fri Sep 3 01:41:35 UTC 2010


Applied to Maverick linux master with small changes to the commit
message to add Lee's SOB and the BugLink.

Thanks,
Leann

On Thu, 2010-09-02 at 15:19 +0100, Lee Jones wrote:
> This patch fixes: 
> 
> BugLink: http://bugs.launchpad.net/bugs/477106
> 
> The following changes since commit 9f02aef9921f0f213a6680768641eb2af6113c3b:
>   Leann Ogasawara (1):
>         UBUNTU: Start new release
> 
> are available in the git repository at:
> 
>   git://kernel.ubuntu.com/lag/ubuntu-maverick.git lp477106-mmc-suspend
> 
> Maxim Levitsky (1):
>       mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
> 
>  drivers/mmc/core/core.c  |   83 +++++++++++++++++++++++++++++++--------------
>  drivers/mmc/core/host.c  |    4 ++
>  include/linux/mmc/host.h |    3 ++
>  3 files changed, 64 insertions(+), 26 deletions(-)
> 
> -------------------------------------------------------------------
> 
> From: Maxim Levitsky <maximlevitsky at gmail.com>
> Date: Wed, 11 Aug 2010 01:01:41 +0000 (-0700)
> Subject: mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume
> 
> 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 at linux-foundation.org: clean up function prototype]
>     [akpm at linux-foundation.org: fix CONFIG_PM-n linkage, small cleanups]
>     [akpm at linux-foundation.org: coding-style fixes]
>     Signed-off-by: Maxim Levitsky <maximlevitsky at gmail.com>
>     Cc: David Brownell <david-b at pacbell.net>
>     Cc: Alan Stern <stern at rowland.harvard.edu>
>     Cc: <linux-mmc at vger.kernel.org>
>     Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
>     Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
>     (cherry picked from commit 4c2ef25fe0b847d2ae818f74758ddb0be1c27d8e)
> 
> ---
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index b69ce91..83240fa 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1057,6 +1057,17 @@ 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);
>  
> @@ -1274,19 +1285,6 @@ int mmc_suspend_host(struct mmc_host *host)
>  	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);
> -			host->pm_flags = 0;
> -			err = 0;
> -		}
>  	}
>  	mmc_bus_put(host);
>  
> @@ -1318,28 +1316,61 @@ 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 4735390..0efe631 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -17,6 +17,7 @@
>  #include <linux/pagemap.h>
>  #include <linux/leds.h>
>  #include <linux/slab.h>
> +#include <linux/suspend.h>
>  
>  #include <linux/mmc/host.h>
>  
> @@ -85,6 +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.
> @@ -133,6 +135,7 @@ int mmc_add_host(struct mmc_host *host)
>  #endif
>  
>  	mmc_start_host(host);
> +	register_pm_notifier(&host->pm_notify);
>  
>  	return 0;
>  }
> @@ -149,6 +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 f65913c..513ff03 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -124,6 +124,7 @@ 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 */
> @@ -183,6 +184,7 @@ 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 */
> @@ -257,6 +259,7 @@ 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)
> 






More information about the kernel-team mailing list