Subject: [PATCH V2 1/1] mmc: start removing enable / disable API

From: [email-masked] (Subhash Jadavani)
Date: Thu, 01 Mar 2012 13:38:51 +0530

On 2/29/2012 12:47 PM, Adrian Hunter wrote:
> Most parts of the enable / disable API are no longer used and
> can be removed.
>
> Cc: Rajendra Nayak<[email-masked]>
> Cc: Venkatraman S<[email-masked]>
> Cc: Kukjin Kim<[email-masked]>
> Cc: Thomas Abraham<[email-masked]>
> Cc: Kyungmin Park<[email-masked]>
> Cc: Sekhar Nori<[email-masked]>
> Cc: Kevin Hilman<[email-masked]>
> Signed-off-by: Adrian Hunter<[email-masked]>
> ---
>   arch/arm/mach-exynos/mach-nuri.c           |    5 +-
>   arch/arm/mach-exynos/mach-universal_c210.c |    9 +-
>   drivers/mmc/core/core.c                    |  187 +++-------------------------
>   drivers/mmc/core/host.c                    |    1 -
>   drivers/mmc/core/host.h                    |    1 -
>   drivers/mmc/host/davinci_mmc.c             |    4 -
>   drivers/mmc/host/omap_hsmmc.c              |   15 +--
>   include/linux/mmc/core.h                   |    1 -
>   include/linux/mmc/host.h                   |   46 +------
>   9 files changed, 27 insertions(+), 242 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/mach-nuri.c b/arch/arm/mach-exynos/mach-nuri.c
> index 644af11..de68248 100644
> --- a/arch/arm/mach-exynos/mach-nuri.c
> +++ b/arch/arm/mach-exynos/mach-nuri.c
> @@ -109,7 +109,7 @@ static struct s3c_sdhci_platdata nuri_hsmmc0_data __initdata = {
>   	.max_width		= 8,
>   	.host_caps		= (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA |
>   				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> -				MMC_CAP_DISABLE | MMC_CAP_ERASE),
> +				MMC_CAP_ERASE),
>   	.cd_type		= S3C_SDHCI_CD_PERMANENT,
>   };
>
> @@ -147,8 +147,7 @@ static struct platform_device emmc_fixed_voltage = {
>   static struct s3c_sdhci_platdata nuri_hsmmc2_data __initdata = {
>   	.max_width		= 4,
>   	.host_caps		= MMC_CAP_4_BIT_DATA |
> -				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> -				MMC_CAP_DISABLE,
> +				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED,
>   	.ext_cd_gpio		= EXYNOS4_GPX3(3),	/* XEINT_27 */
>   	.ext_cd_gpio_invert	= 1,
>   	.cd_type		= S3C_SDHCI_CD_GPIO,
> diff --git a/arch/arm/mach-exynos/mach-universal_c210.c b/arch/arm/mach-exynos/mach-universal_c210.c
> index 9b3fbae..57cfe61 100644
> --- a/arch/arm/mach-exynos/mach-universal_c210.c
> +++ b/arch/arm/mach-exynos/mach-universal_c210.c
> @@ -734,8 +734,7 @@ static struct platform_device universal_gpio_keys = {
>   static struct s3c_sdhci_platdata universal_hsmmc0_data __initdata = {
>   	.max_width		= 8,
>   	.host_caps		= (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA |
> -				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> -				MMC_CAP_DISABLE),
> +				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED),
>   	.cd_type		= S3C_SDHCI_CD_PERMANENT,
>   };
>
> @@ -772,8 +771,7 @@ static struct platform_device mmc0_fixed_voltage = {
>   static struct s3c_sdhci_platdata universal_hsmmc2_data __initdata = {
>   	.max_width		= 4,
>   	.host_caps		= MMC_CAP_4_BIT_DATA |
> -				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> -				MMC_CAP_DISABLE,
> +				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED,
>   	.ext_cd_gpio		= EXYNOS4_GPX3(4),      /* XEINT_28 */
>   	.ext_cd_gpio_invert	= 1,
>   	.cd_type		= S3C_SDHCI_CD_GPIO,
> @@ -783,8 +781,7 @@ static struct s3c_sdhci_platdata universal_hsmmc2_data __initdata = {
>   static struct s3c_sdhci_platdata universal_hsmmc3_data __initdata = {
>   	.max_width		= 4,
>   	.host_caps		= MMC_CAP_4_BIT_DATA |
> -				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> -				MMC_CAP_DISABLE,
> +				MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED,
>   	.cd_type		= S3C_SDHCI_CD_EXTERNAL,
>   };
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 0b317f0..44dd013 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -605,105 +605,6 @@ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
>   EXPORT_SYMBOL(mmc_align_data_size);
>
>   /**
> - *	mmc_host_enable - enable a host.
> - *	@host: mmc host to enable
> - *
> - *	Hosts that support power saving can use the 'enable' and 'disable'
> - *	methods to exit and enter power saving states. For more information
> - *	see comments for struct mmc_host_ops.
> - */
> -int mmc_host_enable(struct mmc_host *host)
> -{
> -	if (!(host->caps&  MMC_CAP_DISABLE))
> -		return 0;
> -
> -	if (host->en_dis_recurs)
> -		return 0;
> -
> -	if (host->nesting_cnt++)
> -		return 0;
> -
> -	cancel_delayed_work_sync(&host->disable);
> -
> -	if (host->enabled)
> -		return 0;
> -
> -	if (host->ops->enable) {
> -		int err;
> -
> -		host->en_dis_recurs = 1;
> -		mmc_host_clk_hold(host);
> -		err = host->ops->enable(host);
> -		mmc_host_clk_release(host);
> -		host->en_dis_recurs = 0;
> -
> -		if (err) {
> -			pr_debug("%s: enable error %d\n",
> -				 mmc_hostname(host), err);
> -			return err;
> -		}
> -	}
> -	host->enabled = 1;
> -	return 0;
> -}
> -EXPORT_SYMBOL(mmc_host_enable);
> -
> -static int mmc_host_do_disable(struct mmc_host *host, int lazy)
> -{
> -	if (host->ops->disable) {
> -		int err;
> -
> -		host->en_dis_recurs = 1;
> -		mmc_host_clk_hold(host);
> -		err = host->ops->disable(host, lazy);
> -		mmc_host_clk_release(host);
> -		host->en_dis_recurs = 0;
> -
> -		if (err<  0) {
> -			pr_debug("%s: disable error %d\n",
> -				 mmc_hostname(host), err);
> -			return err;
> -		}
> -		if (err>  0) {
> -			unsigned long delay = msecs_to_jiffies(err);
> -
> -			mmc_schedule_delayed_work(&host->disable, delay);
> -		}
> -	}
> -	host->enabled = 0;
> -	return 0;
> -}
> -
> -/**
> - *	mmc_host_disable - disable a host.
> - *	@host: mmc host to disable
> - *
> - *	Hosts that support power saving can use the 'enable' and 'disable'
> - *	methods to exit and enter power saving states. For more information
> - *	see comments for struct mmc_host_ops.
> - */
> -int mmc_host_disable(struct mmc_host *host)
> -{
> -	int err;
> -
> -	if (!(host->caps&  MMC_CAP_DISABLE))
> -		return 0;
> -
> -	if (host->en_dis_recurs)
> -		return 0;
> -
> -	if (--host->nesting_cnt)
> -		return 0;
> -
> -	if (!host->enabled)
> -		return 0;
> -
> -	err = mmc_host_do_disable(host, 0);
> -	return err;
> -}
> -EXPORT_SYMBOL(mmc_host_disable);
> -
> -/**
>    *	__mmc_claim_host - exclusively claim a host
>    *	@host: mmc host to claim
>    *	@abort: whether or not the operation should be aborted
> @@ -741,8 +642,8 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort)
>   		wake_up(&host->wq);
>   	spin_unlock_irqrestore(&host->lock, flags);
>   	remove_wait_queue(&host->wq,&wait);
> -	if (!stop)
> -		mmc_host_enable(host);
> +	if (host->ops->enable&&  !stop&&  host->claim_cnt == 1)
Shouldn't we still make sure that clocks are hold (by calling 
mmc_host_clk_hold() ) before calling enable?
> +		host->ops->enable(host);
>   	return stop;
>   }
>
> @@ -767,21 +668,28 @@ int mmc_try_claim_host(struct mmc_host *host)
>   		claimed_host = 1;
>   	}
>   	spin_unlock_irqrestore(&host->lock, flags);
> +	if (host->ops->enable&&  claimed_host&&  host->claim_cnt == 1)
mmc_host_clk_hold() ?
> +		host->ops->enable(host);
>   	return claimed_host;
>   }
>   EXPORT_SYMBOL(mmc_try_claim_host);
>
>   /**
> - *	mmc_do_release_host - release a claimed host
> + *	mmc_release_host - release a host
>    *	@host: mmc host to release
>    *
> - *	If you successfully claimed a host, this function will
> - *	release it again.
> + *	Release a MMC host, allowing others to claim the host
> + *	for their operations.
>    */
> -void mmc_do_release_host(struct mmc_host *host)
> +void mmc_release_host(struct mmc_host *host)
>   {
>   	unsigned long flags;
>
> +	WARN_ON(!host->claimed);
> +
> +	if (host->ops->disable&&  host->claim_cnt == 1)
mmc_host_clk_hold ??
> +		host->ops->disable(host);
> +
>   	spin_lock_irqsave(&host->lock, flags);
>   	if (--host->claim_cnt) {
>   		/* Release for nested claim */
> @@ -793,67 +701,6 @@ void mmc_do_release_host(struct mmc_host *host)
>   		wake_up(&host->wq);
>   	}
>   }
> -EXPORT_SYMBOL(mmc_do_release_host);
> -
> -void mmc_host_deeper_disable(struct work_struct *work)
> -{
> -	struct mmc_host *host =
> -		container_of(work, struct mmc_host, disable.work);
> -
> -	/* If the host is claimed then we do not want to disable it anymore */
> -	if (!mmc_try_claim_host(host))
> -		return;
> -	mmc_host_do_disable(host, 1);
> -	mmc_do_release_host(host);
> -}
> -
> -/**
> - *	mmc_host_lazy_disable - lazily disable a host.
> - *	@host: mmc host to disable
> - *
> - *	Hosts that support power saving can use the 'enable' and 'disable'
> - *	methods to exit and enter power saving states. For more information
> - *	see comments for struct mmc_host_ops.
> - */
> -int mmc_host_lazy_disable(struct mmc_host *host)
> -{
> -	if (!(host->caps&  MMC_CAP_DISABLE))
> -		return 0;
> -
> -	if (host->en_dis_recurs)
> -		return 0;
> -
> -	if (--host->nesting_cnt)
> -		return 0;
> -
> -	if (!host->enabled)
> -		return 0;
> -
> -	if (host->disable_delay) {
> -		mmc_schedule_delayed_work(&host->disable,
> -				msecs_to_jiffies(host->disable_delay));
> -		return 0;
> -	} else
> -		return mmc_host_do_disable(host, 1);
> -}
> -EXPORT_SYMBOL(mmc_host_lazy_disable);
> -
> -/**
> - *	mmc_release_host - release a host
> - *	@host: mmc host to release
> - *
> - *	Release a MMC host, allowing others to claim the host
> - *	for their operations.
> - */
> -void mmc_release_host(struct mmc_host *host)
> -{
> -	WARN_ON(!host->claimed);
> -
> -	mmc_host_lazy_disable(host);
> -
> -	mmc_do_release_host(host);
> -}
> -
>   EXPORT_SYMBOL(mmc_release_host);
>
>   /*
> @@ -2206,8 +2053,6 @@ void mmc_stop_host(struct mmc_host *host)
>   	spin_unlock_irqrestore(&host->lock, flags);
>   #endif
>
> -	if (host->caps&  MMC_CAP_DISABLE)
> -		cancel_delayed_work(&host->disable);
>   	cancel_delayed_work_sync(&host->detect);
>   	mmc_flush_scheduled_work();
>
> @@ -2402,13 +2247,11 @@ int mmc_suspend_host(struct mmc_host *host)
>   {
>   	int err = 0;
>
> -	if (host->caps&  MMC_CAP_DISABLE)
> -		cancel_delayed_work(&host->disable);
>   	cancel_delayed_work(&host->detect);
>   	mmc_flush_scheduled_work();
>   	if (mmc_try_claim_host(host)) {
>   		err = mmc_cache_ctrl(host, 0);
> -		mmc_do_release_host(host);
> +		mmc_release_host(host);
>   	} else {
>   		err = -EBUSY;
>   	}
> @@ -2429,7 +2272,7 @@ int mmc_suspend_host(struct mmc_host *host)
>   			if (host->bus_ops->suspend) {
>   				err = host->bus_ops->suspend(host);
>   			}
> -			mmc_do_release_host(host);
> +			mmc_release_host(host);
>
>   			if (err == -ENOSYS || !host->bus_ops->resume) {
>   				/*
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index c3704e2..91c84c7 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -330,7 +330,6 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
>   	spin_lock_init(&host->lock);
>   	init_waitqueue_head(&host->wq);
>   	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
> -	INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
>   #ifdef CONFIG_PM
>   	host->pm_notify.notifier_call = mmc_pm_notify;
>   #endif
> diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
> index 08a7852..f2ab9e5 100644
> --- a/drivers/mmc/core/host.h
> +++ b/drivers/mmc/core/host.h
> @@ -14,7 +14,6 @@
>
>   int mmc_register_host_class(void);
>   void mmc_unregister_host_class(void);
> -void mmc_host_deeper_disable(struct work_struct *work);
>
>   #endif
>
> diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> index 64a8325..8de9c9b 100644
> --- a/drivers/mmc/host/davinci_mmc.c
> +++ b/drivers/mmc/host/davinci_mmc.c
> @@ -1418,17 +1418,14 @@ static int davinci_mmcsd_suspend(struct device *dev)
>   	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
>   	int ret;
>
> -	mmc_host_enable(host->mmc);
>   	ret = mmc_suspend_host(host->mmc);
>   	if (!ret) {
>   		writel(0, host->base + DAVINCI_MMCIM);
>   		mmc_davinci_reset_ctrl(host, 1);
> -		mmc_host_disable(host->mmc);
>   		clk_disable(host->clk);
>   		host->suspended = 1;
>   	} else {
>   		host->suspended = 0;
> -		mmc_host_disable(host->mmc);
>   	}
>
>   	return ret;
> @@ -1444,7 +1441,6 @@ static int davinci_mmcsd_resume(struct device *dev)
>   		return 0;
>
>   	clk_enable(host->clk);
> -	mmc_host_enable(host->mmc);
>
>   	mmc_davinci_reset_ctrl(host, 0);
>   	ret = mmc_resume_host(host->mmc);
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 36e7f5b..fdb24cf 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -179,7 +179,6 @@ struct omap_hsmmc_host {
>   	int			got_dbclk;
>   	int			response_busy;
>   	int			context_loss;
> -	int			dpm_state;
>   	int			vdd;
>   	int			protect_card;
>   	int			reqs_blocked;
> @@ -1748,7 +1747,7 @@ static int omap_hsmmc_enable_fclk(struct mmc_host *mmc)
>   	return 0;
>   }
>
> -static int omap_hsmmc_disable_fclk(struct mmc_host *mmc, int lazy)
> +static int omap_hsmmc_disable_fclk(struct mmc_host *mmc)
>   {
>   	struct omap_hsmmc_host *host = mmc_priv(mmc);
>
> @@ -1782,15 +1781,8 @@ static int omap_hsmmc_regs_show(struct seq_file *s, void *data)
>   	if (host->pdata->get_context_loss_count)
>   		context_loss = host->pdata->get_context_loss_count(host->dev);
>
> -	seq_printf(s, "mmc%d:\n"
> -			" enabled:\t%d\n"
> -			" dpm_state:\t%d\n"
> -			" nesting_cnt:\t%d\n"
> -			" ctx_loss:\t%d:%d\n"
> -			"\nregs:\n",
> -			mmc->index, mmc->enabled ? 1 : 0,
> -			host->dpm_state, mmc->nesting_cnt,
> -			host->context_loss, context_loss);
> +	seq_printf(s, "mmc%d:\n ctx_loss:\t%d:%d\n\nregs:\n",
> +			mmc->index, host->context_loss, context_loss);
>
>   	if (host->suspended) {
>   		seq_printf(s, "host suspended, can't read registers\n");
> @@ -1930,7 +1922,6 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
>
>   	omap_hsmmc_context_save(host);
>
> -	mmc->caps |= MMC_CAP_DISABLE;
>   	if (host->pdata->controller_flags&  OMAP_HSMMC_BROKEN_MULTIBLOCK_READ) {
>   		dev_info(&pdev->dev, "multiblock reads disabled due to 35xx erratum 2.1.1.128; MMC read performance may suffer\n");
>   		mmc->caps2 |= MMC_CAP2_NO_MULTI_READ;
> diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> index 87a976c..2bfa589 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -175,7 +175,6 @@ extern unsigned int mmc_align_data_size(struct mmc_card *, unsigned int);
>
>   extern int __mmc_claim_host(struct mmc_host *host, atomic_t *abort);
>   extern void mmc_release_host(struct mmc_host *host);
> -extern void mmc_do_release_host(struct mmc_host *host);
>   extern int mmc_try_claim_host(struct mmc_host *host);
>
>   extern int mmc_flush_cache(struct mmc_card *);
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 37147a4..4da98f7 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -80,34 +80,11 @@ struct mmc_ios {
>
>   struct mmc_host_ops {
>   	/*
> -	 * Hosts that support power saving can use the 'enable' and 'disable'
> -	 * methods to exit and enter power saving states. 'enable' is called
> -	 * when the host is claimed and 'disable' is called (or scheduled with
> -	 * a delay) when the host is released. The 'disable' is scheduled if
> -	 * the disable delay set by 'mmc_set_disable_delay()' is non-zero,
> -	 * otherwise 'disable' is called immediately. 'disable' may be
> -	 * scheduled repeatedly, to permit ever greater power saving at the
> -	 * expense of ever greater latency to re-enable. Rescheduling is
> -	 * determined by the return value of the 'disable' method. A positive
> -	 * value gives the delay in milliseconds.
> -	 *
> -	 * In the case where a host function (like set_ios) may be called
> -	 * with or without the host claimed, enabling and disabling can be
> -	 * done directly and will nest correctly. Call 'mmc_host_enable()' and
> -	 * 'mmc_host_lazy_disable()' for this purpose, but note that these
> -	 * functions must be paired.
> -	 *
> -	 * Alternatively, 'mmc_host_enable()' may be paired with
> -	 * 'mmc_host_disable()' which calls 'disable' immediately.  In this
> -	 * case the 'disable' method will be called with 'lazy' set to 0.
> -	 * This is mainly useful for error paths.
> -	 *
> -	 * Because lazy disable may be called from a work queue, the 'disable'
> -	 * method must claim the host when 'lazy' != 0, which will work
> -	 * correctly because recursion is detected and handled.
> +	 * 'enable' is called when the host is claimed and 'disable' is called
> +	 * when the host is released. 'enable' and 'disable' are deprecated.
>   	 */
>   	int (*enable)(struct mmc_host *host);
> -	int (*disable)(struct mmc_host *host, int lazy);
> +	int (*disable)(struct mmc_host *host);
>   	/*
>   	 * It is optional for the host to implement pre_req and post_req in
>   	 * order to support double buffering of requests (prepare one
> @@ -218,7 +195,7 @@ struct mmc_host {
>   #define MMC_CAP_SPI		(1<<  4)	/* Talks only SPI protocols */
>   #define MMC_CAP_NEEDS_POLL	(1<<  5)	/* Needs polling for card-detection */
>   #define MMC_CAP_8_BIT_DATA	(1<<  6)	/* Can the host do 8 bit transfers */
> -#define MMC_CAP_DISABLE		(1<<  7)	/* Can the host be disabled */
> +
>   #define MMC_CAP_NONREMOVABLE	(1<<  8)	/* Nonremovable e.g. eMMC */
>   #define MMC_CAP_WAIT_WHILE_BUSY	(1<<  9)	/* Waits while card is busy */
>   #define MMC_CAP_ERASE		(1<<  10)	/* Allow erase/trim commands */
> @@ -301,13 +278,7 @@ struct mmc_host {
>   	unsigned int		removed:1;	/* host is being removed */
>   #endif
>
> -	/* 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 */
> -	struct delayed_work	disable;	/* disabling work */
>
>   	struct mmc_card		*card;		/* device attached to this host */
>
> @@ -407,17 +378,8 @@ int mmc_card_awake(struct mmc_host *host);
>   int mmc_card_sleep(struct mmc_host *host);
>   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)
> -{
> -	host->disable_delay = disable_delay;
> -}
> -
>   /* Module parameter */
>   extern bool mmc_assume_removable;
>