On 11 May 2012 17:14, Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> wrote:
> Hi Girish,
>
>
> On 5/7/2012 7:11 PM, Girish K S 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>
>>
>> changes in v3:
>> This version addresses the review comments given by Subhash and Ulf
>> changes in v2:
>> This version addresses the changes suggested by Ulf
>> ---
>> drivers/mmc/core/core.c | 98
>> +++++++++++++++-------------------------------
>> drivers/mmc/core/core.h | 1 +
>> drivers/mmc/core/mmc.c | 73 ++++++++++++++++++++++++++++------
>> include/linux/mmc/card.h | 8 +++-
>> include/linux/mmc/host.h | 9 ++--
>> 5 files changed, 105 insertions(+), 84 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index ba821fe..3db3b32 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.
>> */
>> @@ -2081,9 +2021,16 @@ void mmc_stop_host(struct mmc_host *host)
>>
>> /* clear pm flags now and let card drivers set them as needed */
>> host->pm_flags = 0;
>> -
>> mmc_bus_get(host);
>> if (host->bus_ops&& !host->bus_dead) {
>>
>> +
>> + if (host->bus_ops->poweroff_notify) {
>> + int err = host->bus_ops->poweroff_notify(host);
>> + if (err&& err != -EOPNOTSUPP)
>>
>> + pr_info("%s: error [%d] in poweroff
>> notify\n",
>> + mmc_hostname(host), err);
>> + }
>> +
>> /* Calling bus_ops->remove() with a claimed host can
>> deadlock */
>> if (host->bus_ops->remove)
>> host->bus_ops->remove(host);
>> @@ -2093,6 +2040,7 @@ 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);
>> @@ -2119,6 +2067,13 @@ int mmc_power_save_host(struct mmc_host *host)
>>
>> if (host->bus_ops->power_save)
>> ret = host->bus_ops->power_save(host);
>> + host->poweroff_notify_type = MMC_HOST_PW_OFF_NOTIFY_SHORT;
>
> Before sending this short power off notification, shouldn't we make sure
> that host has defined MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND cap?
>>
In mmc_power_save_host, we are powering OFF the eMMC and not
suspending it with SLEEP command. So, the flag is unrelated here.
The MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND is introduced to have the
choice in mmc_suspend, where we can potentially switch off VCCQ with
power OFF notify instead of just SLEEP command and switch off VCC
earlier.
>> + if (host->bus_ops->poweroff_notify) {
>> + int err = host->bus_ops->poweroff_notify(host);
>> + if (err&& err != -EOPNOTSUPP)
>>
>> + pr_info("%s: error [%d] in poweroff notify\n",
>> + mmc_hostname(host), err);
>> + }
>>
>> mmc_bus_put(host);
>>
>> @@ -2142,7 +2097,6 @@ int mmc_power_restore_host(struct mmc_host *host)
>> mmc_bus_put(host);
>> return -EINVAL;
>> }
>> -
>> mmc_power_up(host);
>> ret = host->bus_ops->power_restore(host);
>>
>> @@ -2161,8 +2115,11 @@ 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 +2136,11 @@ 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);
>>
>> @@ -2373,12 +2333,18 @@ 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;
>> + host->poweroff_notify_type = MMC_HOST_PW_OFF_NOTIFY_SHORT;
>
> Before sending this short power off notification, shouldn't we make sure
> that host has defined MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND cap?
The same explanation is same as above. We are powering OFF eMMC here
and not sending the SLEEP command.
>>
>> spin_unlock_irqrestore(&host->lock, flags);
>> cancel_delayed_work_sync(&host->detect);
>>
>> if (!host->bus_ops || host->bus_ops->suspend)
>> break;
>> + if (host->bus_ops->poweroff_notify) {
>> + int err = host->bus_ops->poweroff_notify(host);
>> + if (err&& err != -EOPNOTSUPP)
>>
>> + pr_info("%s: error [%d] in poweroff
>> notify\n",
>> + mmc_hostname(host), err);
>> + }
>>
>> /* Calling bus_ops->remove() with a claimed host can
>> deadlock */
>> if (host->bus_ops->remove)
>> @@ -2397,7 +2363,7 @@ 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;
>> + host->poweroff_notify_type = MMC_HOST_PW_OFF_NOTIFY_LONG;
>> spin_unlock_irqrestore(&host->lock, flags);
>> mmc_detect_change(host, 0);
>>
>> 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..a86e5f8 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1282,6 +1282,47 @@ 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 = -EOPNOTSUPP;
>> +
>> + card = host->card;
>> +
>> + /*
>> + * Send power notify command only if card
>> + * is mmc and notify state is powered ON
>> + */
>> + if (mmc_card_can_poweroff_notify(host->card)) {
>> + if (host->poweroff_notify_type ==
>> + MMC_HOST_PW_OFF_NOTIFY_SHORT) {
>> + notify_type = EXT_CSD_POWER_OFF_SHORT;
>> + timeout = card->ext_csd.generic_cmd6_time;
>> + } else {
>
> poweroff_notify_type can take 3 different values.
> #define MMC_HOST_PW_OFF_NOTIFY_NONE 0
> #define MMC_HOST_PW_OFF_NOTIFY_SHORT 1
> #define MMC_HOST_PW_OFF_NOTIFY_LONG 2
>
> So shouldn't we have explicit check for NOTIFY_LONG?
> else if (notify_type == LONG) { ... }
> else {error printing?}
>
May be, you are pointing to a situation where some host controller
driver set power_notify_type to MMC_HOST_PW_NOTIFY_NONE but enable
MMC_CAP2_POWEROFF_NOTIFY. We can add a check in mmc_init_card, where
we check this possibility before setting EXT_CSD_POWER_ON.
>> + notify_type = EXT_CSD_POWER_OFF_LONG;
>> + timeout = card->ext_csd.power_off_longtime;
>> + }
>> +
>> + mmc_claim_host(host);
>> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> + EXT_CSD_POWER_OFF_NOTIFICATION,
>> + notify_type, timeout);
>> + mmc_release_host(host);
>> +
>> + 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);
>> + else
>> + card->poweroff_notify_state =
>> + MMC_NO_POWER_NOTIFICATION;
>
> Just wondering, if we should really to set the notify_state to
> NO_POWER_NOTIFICATION incase if err = -EBADMSG ?
Perhaps it does not matter. We will proceed with powering OFF the eMMC
even in case of this error and next time, poweroff_notify_state will
get re-initialized from mmc_init_card.
>>
>> + }
>> +
>> + return err;
>> +}
>> +
>> /*
>> * Host is being removed. Free up the current card.
>> */
>> @@ -1341,15 +1382,21 @@ 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 (mmc_card_can_poweroff_notify(host->card)&&
>> + (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 +1415,11 @@ 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 +1477,7 @@ static const struct mmc_bus_ops mmc_ops = {
>> .resume = NULL,
>> .power_restore = mmc_power_restore,
>> .alive = mmc_alive,
>> + .poweroff_notify = mmc_poweroff_notify,
>> };
>>
>> static const struct mmc_bus_ops mmc_ops_unsafe = {
>> @@ -1441,6 +1489,7 @@ 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/card.h b/include/linux/mmc/card.h
>> index 629b823..a6cdc43 100644
>> --- a/include/linux/mmc/card.h
>> +++ b/include/linux/mmc/card.h
>> @@ -238,8 +238,6 @@ struct mmc_card {
>> 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
>> */
>> @@ -465,6 +463,12 @@ static inline int mmc_card_long_read_time(const
>> struct mmc_card *c)
>> return c->quirks& MMC_QUIRK_LONG_READ_TIME;
>>
>> }
>>
>> +static inline int mmc_card_can_poweroff_notify(const struct mmc_card *c)
>> +{
>> + return c&& mmc_card_mmc(c)&&
>> + (c->poweroff_notify_state ==
>> MMC_POWERED_ON);
>> +}
>> +
>
> I guess you may want to move this function in drivers/mmc/core/core.c along
> with other mmc_can_* function in same file. Look for mmc_can_sanitize() or
> mmc_can_discard() functions as example.
>
Ok
>
>> #define mmc_card_name(c) ((c)->cid.prod_name)
>> #define mmc_card_id(c) (dev_name(&(c)->dev))
>>
>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>> index 0707d22..aad894e 100644
>> --- a/include/linux/mmc/host.h
>> +++ b/include/linux/mmc/host.h
>> @@ -238,12 +238,13 @@ 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;
>> -#define MMC_HOST_PW_NOTIFY_NONE 0
>> -#define MMC_HOST_PW_NOTIFY_SHORT 1
>> -#define MMC_HOST_PW_NOTIFY_LONG 2
>> + unsigned int poweroff_notify_type;
>
> Can you add additional tab to make poweroff_notify_state aligned to other
> members in this same structure?
Ok
>
>> +#define MMC_HOST_PW_OFF_NOTIFY_NONE 0
>> +#define MMC_HOST_PW_OFF_NOTIFY_SHORT 1
>> +#define MMC_HOST_PW_OFF_NOTIFY_LONG 2
>>
>> #ifdef CONFIG_MMC_CLKGATE
>> int clk_requests; /* internal reference
>> counter */
>
>
Ulf, Subhash, please come back with additional comments (if any). We
can then go ahead with submission of the final version of this
feature.
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