Re: [PATCH] MMC-4.5 Power OFF Notify rework

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On 19 April 2012 18:11, Girish K S <girish.shivananjappa@xxxxxxxxxx> wrote:
> This is a rework of the existing POWER OFF NOTIFY patch. The current problem
> with the patch comes from the ambiguity on the usage of POWER OFF NOTIFY
> together with SLEEP and misunderstanding on the usage of MMC_POWER_OFF
> power_mode from mmc_set_ios in different host controller drivers.
>
> This new patch works around this problem by adding a new host CAP,
> MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND, which when set sends a
> POWER OFF NOTIFY from mmc_suspend instead of SLEEP. It is expected that host
> controller drivers will set this CAP, if they switch off both Vcc and Vccq
> from MMC_POWER_OFF condition within mmc_set_ios. However, note that there
> is no harm in sending MMC_POWER_NOTIFY even if Vccq is not switched off.
>
> This patch also sends POWER OFF NOTIFY from power management routines (e.g.
> mmc_power_save_host, mmc_pm_notify/PM_SUSPEND_PREPARE, mmc_stop_host), which
> does reinitialization of the eMMC on the return path of the power management
> routines (e.g. mmc_power_restore_host, mmc_pm_notify/PM_POST_RESTORE,
> mmc_start_host).
>
> This patch sets POWER_OFF_NOTIFICATION to POWER_OFF_SHORT if it is sent from
> the suspend sequence. If it is sent from shutdown sequence then it is set to
> POWER_OFF_LONG.
>
> Previuos implementation of PowerOff Notify as a core function is replaced as
> a device's bus operation.
>
> Signed-off-by: Saugata Das <saugata.das@xxxxxxxxxx>
> Signed-off-by: Girish K S <girish.shivananjappa@xxxxxxxxxx>
> ---
>  drivers/mmc/core/core.c  |   83 ++++++++++-----------------------------------
>  drivers/mmc/core/core.h  |    1 +
>  drivers/mmc/core/mmc.c   |   75 +++++++++++++++++++++++++++++++++++-------
>  include/linux/mmc/host.h |    1 +
>  4 files changed, 84 insertions(+), 76 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index e541efb..4b8b2c1 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1100,48 +1100,6 @@ void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
>        mmc_host_clk_release(host);
>  }
>
> -static void mmc_poweroff_notify(struct mmc_host *host)
> -{
> -       struct mmc_card *card;
> -       unsigned int timeout;
> -       unsigned int notify_type = EXT_CSD_NO_POWER_NOTIFICATION;
> -       int err = 0;
> -
> -       card = host->card;
> -       mmc_claim_host(host);
> -
> -       /*
> -        * Send power notify command only if card
> -        * is mmc and notify state is powered ON
> -        */
> -       if (card && mmc_card_mmc(card) &&
> -           (card->poweroff_notify_state == MMC_POWERED_ON)) {
> -
> -               if (host->power_notify_type == MMC_HOST_PW_NOTIFY_SHORT) {
> -                       notify_type = EXT_CSD_POWER_OFF_SHORT;
> -                       timeout = card->ext_csd.generic_cmd6_time;
> -                       card->poweroff_notify_state = MMC_POWEROFF_SHORT;
> -               } else {
> -                       notify_type = EXT_CSD_POWER_OFF_LONG;
> -                       timeout = card->ext_csd.power_off_longtime;
> -                       card->poweroff_notify_state = MMC_POWEROFF_LONG;
> -               }
> -
> -               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> -                                EXT_CSD_POWER_OFF_NOTIFICATION,
> -                                notify_type, timeout);
> -
> -               if (err && err != -EBADMSG)
> -                       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 */
> -               card->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION;
> -       }
> -       mmc_release_host(host);
> -}
> -
>  /*
>  * Apply power to the MMC stack.  This is a two-stage process.
>  * First, we enable power to the card without the clock running.
> @@ -1198,30 +1156,12 @@ static void mmc_power_up(struct mmc_host *host)
>
>  void mmc_power_off(struct mmc_host *host)
>  {
> -       int err = 0;
>        mmc_host_clk_hold(host);
>
>        host->ios.clock = 0;
>        host->ios.vdd = 0;
>
>        /*
> -        * For eMMC 4.5 device send AWAKE command before
> -        * POWER_OFF_NOTIFY command, because in sleep state
> -        * eMMC 4.5 devices respond to only RESET and AWAKE cmd
> -        */
> -       if (host->card && mmc_card_is_sleep(host->card) &&
> -           host->bus_ops->resume) {
> -               err = host->bus_ops->resume(host);
> -
> -               if (!err)
> -                       mmc_poweroff_notify(host);
> -               else
> -                       pr_warning("%s: error %d during resume "
> -                                  "(continue with poweroff sequence)\n",
> -                                  mmc_hostname(host), err);
> -       }
> -
> -       /*
>         * Reset ocr mask to be the highest possible voltage supported for
>         * this mmc host. This value will be used at next power up.
>         */
> @@ -2084,6 +2024,9 @@ void mmc_stop_host(struct mmc_host *host)
>
>        mmc_bus_get(host);
>        if (host->bus_ops && !host->bus_dead) {
> +               if (host->bus_ops->poweroff_notify)
> +                       host->bus_ops->poweroff_notify(host);
> +
>                /* Calling bus_ops->remove() with a claimed host can deadlock */
>                if (host->bus_ops->remove)
>                        host->bus_ops->remove(host);
> @@ -2093,6 +2036,7 @@ void mmc_stop_host(struct mmc_host *host)
>                mmc_power_off(host);
>                mmc_release_host(host);
>                mmc_bus_put(host);
> +
>                return;
>        }
>        mmc_bus_put(host);
> @@ -2119,7 +2063,9 @@ int mmc_power_save_host(struct mmc_host *host)
>
>        if (host->bus_ops->power_save)
>                ret = host->bus_ops->power_save(host);
> -
> +       host->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
> +       if (host->bus_ops->poweroff_notify)
> +               host->bus_ops->poweroff_notify(host);
>        mmc_bus_put(host);
>
>        mmc_power_off(host);
> @@ -2142,7 +2088,7 @@ int mmc_power_restore_host(struct mmc_host *host)
>                mmc_bus_put(host);
>                return -EINVAL;
>        }
> -
> +       host->power_notify_type = MMC_HOST_PW_NOTIFY_LONG;
>        mmc_power_up(host);
>        ret = host->bus_ops->power_restore(host);
>
> @@ -2161,8 +2107,11 @@ int mmc_card_awake(struct mmc_host *host)
>
>        mmc_bus_get(host);
>
> -       if (host->bus_ops && !host->bus_dead && host->bus_ops->awake)
> +       if (host->bus_ops && !host->bus_dead && host->bus_ops->awake) {
>                err = host->bus_ops->awake(host);
> +               if (!err)
> +                       mmc_card_clr_sleep(host->card);
> +       }
>
>        mmc_bus_put(host);
>
> @@ -2179,8 +2128,11 @@ int mmc_card_sleep(struct mmc_host *host)
>
>        mmc_bus_get(host);
>
> -       if (host->bus_ops && !host->bus_dead && host->bus_ops->sleep)
> +       if (host->bus_ops && !host->bus_dead && host->bus_ops->sleep) {
>                err = host->bus_ops->sleep(host);
> +               if (!err)
> +                       mmc_card_set_sleep(host->card);
> +       }
>
>        mmc_bus_put(host);
>
> @@ -2394,6 +2346,8 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>
>                if (!host->bus_ops || host->bus_ops->suspend)
>                        break;
> +               if (host->bus_ops->poweroff_notify)
> +                       host->bus_ops->poweroff_notify(host);
>
>                /* Calling bus_ops->remove() with a claimed host can deadlock */
>                if (host->bus_ops->remove)
> @@ -2403,6 +2357,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>                mmc_detach_bus(host);
>                mmc_power_off(host);
>                mmc_release_host(host);
> +
>                host->pm_flags = 0;
>                break;
>
> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> index 3bdafbc..351cbbe 100644
> --- a/drivers/mmc/core/core.h
> +++ b/drivers/mmc/core/core.h
> @@ -25,6 +25,7 @@ struct mmc_bus_ops {
>        int (*power_save)(struct mmc_host *);
>        int (*power_restore)(struct mmc_host *);
>        int (*alive)(struct mmc_host *);
> +       int (*poweroff_notify)(struct mmc_host *);
>  };
>
>  void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 54df5ad..62bdee6 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1282,6 +1282,50 @@ err:
>        return err;
>  }
>
> +static int mmc_poweroff_notify(struct mmc_host *host)
> +{
> +       struct mmc_card *card;
> +       unsigned int timeout;
> +       unsigned int notify_type = EXT_CSD_NO_POWER_NOTIFICATION;
> +       int err = -EINVAL;
> +
> +       card = host->card;
> +       mmc_claim_host(host);
> +
> +       /*
> +        * Send power notify command only if card
> +        * is mmc and notify state is powered ON
> +        */
> +       if (card && mmc_card_mmc(card) &&
> +           (card->poweroff_notify_state == MMC_POWERED_ON)) {
> +
> +               if (host->power_notify_type == MMC_HOST_PW_NOTIFY_SHORT) {
> +                       notify_type = EXT_CSD_POWER_OFF_SHORT;
> +                       timeout = card->ext_csd.generic_cmd6_time;
> +                       card->poweroff_notify_state = MMC_POWEROFF_SHORT;
> +               } else {
> +                       notify_type = EXT_CSD_POWER_OFF_LONG;
> +                       timeout = card->ext_csd.power_off_longtime;
> +                       card->poweroff_notify_state = MMC_POWEROFF_LONG;
> +               }
> +
> +               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> +                                EXT_CSD_POWER_OFF_NOTIFICATION,
> +                                notify_type, timeout);
> +
> +               if (err && err != -EBADMSG)
> +                       pr_err("%s: Device failed to respond within %d "
> +                              "poweroff time. Forcefully powering down "
> +                              "the device\n", mmc_hostname(host), timeout);
> +
> +               /* Set the card state to no notification after the poweroff */
> +               card->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION;
> +       }
> +       mmc_release_host(host);
> +
> +       return err;
> +}
> +
>  /*
>  * Host is being removed. Free up the current card.
>  */
> @@ -1341,15 +1385,20 @@ static int mmc_suspend(struct mmc_host *host)
>        BUG_ON(!host);
>        BUG_ON(!host->card);
>
> -       mmc_claim_host(host);
> -       if (mmc_card_can_sleep(host)) {
> -               err = mmc_card_sleep(host);
> -               if (!err)
> -                       mmc_card_set_sleep(host->card);
> -       } else if (!mmc_host_is_spi(host))
> -               mmc_deselect_cards(host);
> -       host->card->state &= ~(MMC_STATE_HIGHSPEED | MMC_STATE_HIGHSPEED_200);
> -       mmc_release_host(host);
> +       if (host->caps2 & MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND) {
> +               err = mmc_poweroff_notify(host);
> +       } else {
> +               mmc_claim_host(host);
> +               if (mmc_card_can_sleep(host))
> +                       err = mmc_card_sleep(host);
> +               else if (!mmc_host_is_spi(host))
> +                       mmc_deselect_cards(host);
> +               mmc_release_host(host);
> +       }
> +
> +       if (!err)
> +               host->card->state &=
> +                       ~(MMC_STATE_HIGHSPEED | MMC_STATE_HIGHSPEED_200);
>
>        return err;
>  }
> @@ -1368,11 +1417,11 @@ static int mmc_resume(struct mmc_host *host)
>        BUG_ON(!host->card);
>
>        mmc_claim_host(host);
> -       if (mmc_card_is_sleep(host->card)) {
> +       if (mmc_card_is_sleep(host->card))
>                err = mmc_card_awake(host);
> -               mmc_card_clr_sleep(host->card);
> -       } else
> +       else
>                err = mmc_init_card(host, host->ocr, host->card);
> +
>        mmc_release_host(host);
>
>        return err;
> @@ -1430,6 +1479,7 @@ static const struct mmc_bus_ops mmc_ops = {
>        .resume = NULL,
>        .power_restore = mmc_power_restore,
>        .alive = mmc_alive,
> +       .poweroff_notify = NULL,
>  };
>
>  static const struct mmc_bus_ops mmc_ops_unsafe = {
> @@ -1441,6 +1491,7 @@ static const struct mmc_bus_ops mmc_ops_unsafe = {
>        .resume = mmc_resume,
>        .power_restore = mmc_power_restore,
>        .alive = mmc_alive,
> +       .poweroff_notify = mmc_poweroff_notify,
>  };
>
>  static void mmc_attach_bus_ops(struct mmc_host *host)
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index cbde4b7..cf44a6f 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -238,6 +238,7 @@ struct mmc_host {
>  #define MMC_CAP2_BROKEN_VOLTAGE        (1 << 7)        /* Use the broken voltage */
>  #define MMC_CAP2_DETECT_ON_ERR (1 << 8)        /* On I/O err check card removal */
>  #define MMC_CAP2_HC_ERASE_SZ   (1 << 9)        /* High-capacity erase size */
> +#define MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND (1 << 10)
>
>        mmc_pm_flag_t           pm_caps;        /* supported pm features */
>        unsigned int        power_notify_type;

Hi Ulf,
need your comment on the above.
> --
> 1.7.1
>
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