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From: Ulf Hansson <ulf.hansson@stericsson.com>
To: Girish K S <girish.shivananjappa@linaro.org>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	"patches@linaro.org" <patches@linaro.org>,
	"saugata.das@linaro.org" <saugata.das@linaro.org>
Subject: Re: [PATCH] MMC-4.5 Power OFF Notify rework
Date: Fri, 20 Apr 2012 14:55:34 +0200	[thread overview]
Message-ID: <4F915CC6.2040500@stericsson.com> (raw)
In-Reply-To: <CAGxe1ZH=NpTWNY_MxTF6iDAqJBtP-PsR9EO_nvWFCU6kLGGwvQ@mail.gmail.com>

On 04/20/2012 01:33 PM, Girish K S wrote:
> On 19 April 2012 18:11, Girish K S<girish.shivananjappa@linaro.org>  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@linaro.org>
>> Signed-off-by: Girish K S<girish.shivananjappa@linaro.org>
>> ---
>>   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
>>

I will definitely look into it beginning of next week. Please be 
patient. :-)

Kind regards
Ulf Hansson



  reply	other threads:[~2012-04-20 12:55 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-19 12:41 [PATCH] MMC-4.5 Power OFF Notify rework Girish K S
2012-04-20 11:33 ` Girish K S
2012-04-20 12:55   ` Ulf Hansson [this message]
2012-04-23 14:11   ` Ulf Hansson
2012-04-27  4:40     ` Girish K S
2012-04-27  7:40       ` Ulf Hansson
2012-04-27  8:42         ` Saugata Das
2012-04-27  8:53           ` Girish K S
  -- strict thread matches above, loose matches on Subject: below --
2012-06-15  4:08 [PATCH] MMC-4.5 Power OFF Notify Rework Saugata Das
2012-06-15 12:57 ` S, Venkatraman
2012-06-29  9:03 Saugata Das
2012-08-20 14:13 ` Ulf Hansson

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