Re: [PATCH V6 RESEND 2/2] mmc: core: Add Poweroff Notify handling eMMC 4.5

[Chris Ball <cjb@laptop.org>]

Hi Girish,

On Fri, Sep 16 2011, Girish K S wrote:
> This patch adds the power off notification handling
> during suspend and system poweroff.
> For suspend mode short timeout is used, whereas for the
> normal poweroff long timeout is used.
>
> Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
> ---
>  drivers/mmc/core/core.c  |   34 ++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/mmc.c   |    5 ++++-
>  drivers/mmc/host/sdhci.c |   10 ++++++++++
>  include/linux/mmc/card.h |   19 +++++++++++++++++++
>  include/linux/mmc/host.h |    4 ++++
>  5 files changed, 71 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 91a0a74..157060f 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1130,9 +1130,41 @@ static void mmc_power_up(struct mmc_host *host)
>  
>  static void mmc_power_off(struct mmc_host *host)
>  {
> +	struct mmc_card *card = host->card;
> +	unsigned int notify_type;
> +	unsigned int timeout;
> +	int err;
> +
>  	host->ios.clock = 0;
>  	host->ios.vdd = 0;
>  
> +	if (card != NULL && mmc_card_mmc(card) &&
> +		(mmc_card_powernotify_on(card))) {
> +
> +		if (host->power_notify_type == MMC_HOST_PW_NOTIFY_SHORT) {
> +			notify_type = EXT_CSD_POWER_OFF_SHORT;
> +			timeout = card->ext_csd.generic_cmd6_time;
> +			mmc_card_set_powernotify_short(card);
> +		} else {
> +			notify_type = EXT_CSD_POWER_OFF_LONG;
> +			timeout = card->ext_csd.power_off_longtime;
> +			mmc_card_set_powernotify_long(card);
> +		}
> +
> +		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> +				EXT_CSD_POWER_OFF_NOTIFICATION,
> +				notify_type, timeout);
> +
> +		if (err && err != -EBADMSG)
> +			printk(KERN_ERR "Device failed to respond "
> +					"within %d poweroff time."
> +					"forcefully powering down"
> +					"the device\n", timeout);

You don't have any space between ".f" in the message.  I suggest:

                        pr_err("Device failed to respond within %d poweroff "
                               "time. Forcefully powering down the device\n",
                               timeout);
> +
> +		/*Set the card state to no notification after the poweroff*/

A space between /* */.

> +		mmc_card_set_powernotify_off(card);
> +	}
> +
>  	/*
>  	 * Reset ocr mask to be the highest possible voltage supported for
>  	 * this mmc host. This value will be used at next power up.
> @@ -2022,6 +2054,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>  
>  		spin_lock_irqsave(&host->lock, flags);
>  		host->rescan_disable = 1;
> +		host->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
>  		spin_unlock_irqrestore(&host->lock, flags);
>  		cancel_delayed_work_sync(&host->detect);
>  
> @@ -2044,6 +2077,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>  
>  		spin_lock_irqsave(&host->lock, flags);
>  		host->rescan_disable = 0;
> +		host->power_notify_type = MMC_HOST_PW_NOTIFY_LONG;
>  		spin_unlock_irqrestore(&host->lock, flags);
>  		mmc_detect_change(host, 0);
>  
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 2f06b37..63cc77b 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -715,7 +715,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>  	 * If the host supports the power_off_notify capability then
>  	 * set the notification byte in the ext_csd register of device
>  	 */
> -	if (host->caps & MMC_CAP_POWER_OFF_NOTIFY) {
> +	if ((host->caps & MMC_CAP_POWER_OFF_NOTIFY)	&&

The && is indented weirdly.  Just use a space between ") &&".

> +		(mmc_card_powernotify_off(card))) {
>  		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>  				EXT_CSD_POWER_OFF_NOTIFICATION,
>  				EXT_CSD_POWER_ON,
> @@ -724,6 +725,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>  			goto free_card;
>  	}
>  
> +	if (!err)
> +		mmc_card_set_powernotify_on(card);

Extra newline needed here, as there was before you added these two lines.

>  	/*
>  	 * Activate high speed (if supported)
>  	 */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 0e02cc1..92ea734 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2566,6 +2566,16 @@ int sdhci_add_host(struct sdhci_host *host)
>  	if (caps[1] & SDHCI_DRIVER_TYPE_D)
>  		mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
>  
> +	/*
> +	 * If Notify capability is enabled and
> +	 * notify type is not initialised by host, set default to
> +	 * long power off notify timeout value
> +	 */
> +	if (mmc->caps & MMC_CAP_POWER_OFF_NOTIFY)
> +		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
> +	else
> +		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_NONE;
> +

The comment says it sets the default to long power off if power_notify_type
is unset, but the code sets power_notify_type to short power off regardless
of whether power_notify_type was set.  The comment and code should agree.

>  	/* Initial value for re-tuning timer count */
>  	host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
>  			      SDHCI_RETUNING_TIMER_COUNT_SHIFT;
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 2bf2843..1d6a832 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -190,6 +190,11 @@ struct mmc_card {
>  #define MMC_QUIRK_DISABLE_CD	(1<<5)		/* disconnect CD/DAT[3] resistor */
>  #define MMC_QUIRK_INAND_CMD38	(1<<6)		/* iNAND devices have broken CMD38 */
>  #define MMC_QUIRK_BLK_NO_CMD23	(1<<7)		/* Avoid CMD23 for regular multiblock */
> +	unsigned int    poweroff_notify_state;/*eMMC4.5 notify feature  */
> +#define MMC_NO_POWER_NOTIFICATION  0
> +#define MMC_POWERED_ON     1
> +#define MMC_POWEROFF_SHORT 2
> +#define MMC_POWEROFF_LONG  3
>  
>  	unsigned int		erase_size;	/* erase size in sectors */
>   	unsigned int		erase_shift;	/* if erase unit is power 2 */
> @@ -325,6 +330,20 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
>  #define mmc_sd_card_set_uhs(c) ((c)->state |= MMC_STATE_ULTRAHIGHSPEED)
>  #define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
>  
> +#define mmc_card_powernotify_on(c)     \
> +		((c)->poweroff_notify_state == MMC_POWERED_ON)
> +#define mmc_card_powernotify_off(c)    \
> +		((c)->poweroff_notify_state == MMC_NO_POWER_NOTIFICATION)
> +
> +#define mmc_card_set_powernotify_off(c)    \
> +		((c)->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION)
> +#define mmc_card_set_powernotify_on(c) \
> +		((c)->poweroff_notify_state = MMC_POWERED_ON)
> +#define mmc_card_set_powernotify_short(c)  \
> +		((c)->poweroff_notify_state = MMC_POWEROFF_SHORT)
> +#define mmc_card_set_powernotify_long(c)   \
> +		((c)->poweroff_notify_state = MMC_POWEROFF_LONG)
> +

I don't think these macros need to exist.  You can already do the same
thing in one line of code, and it would be clearer to be modifying/testing
poweroff_notify_state directly.  The only case where it might save enough
column space to allow fitting everything on one line is for
MMC_NO_POWER_NOTIFICATION, but maybe that's just a sign that this
#define should be made shorter somehow.

Thanks!  Please could you rebase against mmc-next, fix, and resend?

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child