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 V2] MMC-4.5 Power OFF Notify rework
Date: Mon, 30 Apr 2012 10:39:29 +0200 [thread overview]
Message-ID: <4F9E4FC1.3010505@stericsson.com> (raw)
In-Reply-To: <1335766496-15966-1-git-send-email-girish.shivananjappa@linaro.org>
On 04/30/2012 08:14 AM, 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@linaro.org>
> Signed-off-by: Girish K S<girish.shivananjappa@linaro.org>
> ---
> drivers/mmc/core/core.c | 95 +++++++++++++++------------------------------
> drivers/mmc/core/core.h | 1 +
> drivers/mmc/core/mmc.c | 76 +++++++++++++++++++++++++++++++------
> include/linux/mmc/host.h | 1 +
> 4 files changed, 98 insertions(+), 75 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index ba821fe..7f5461e 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 +2024,14 @@ 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) {
> + int err = host->bus_ops->poweroff_notify(host);
> + if (err)
> + pr_info("%s: error [%x] 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 +2041,7 @@ 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 +2068,13 @@ 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) {
> + int err = host->bus_ops->poweroff_notify(host);
> + if (err)
> + pr_info("%s: error [%x] in poweroff notify\n",
> + mmc_hostname(host), err);
> + }
>
> mmc_bus_put(host);
>
> @@ -2142,7 +2098,7 @@ 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 +2117,11 @@ 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 +2138,11 @@ 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);
>
> @@ -2379,6 +2341,12 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>
> 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)
> + pr_info("%s: error [%x] in poweroff notify\n",
> + mmc_hostname(host), err);
> + }
>
> /* Calling bus_ops->remove() with a claimed host can deadlock */
> if (host->bus_ops->remove)
> @@ -2388,6 +2356,7 @@ 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..11ab536 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 = -EOPNOTSUPP;
> +
> + 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 +1385,21 @@ 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 ((host->card)&& mmc_card_mmc(host->card)&&
> + (host->caps2& MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND)) {
> + err = mmc_poweroff_notify(host);
This still wont work. What if the card supports sleep but not
poweroff_notify. At the same time the host is able to cut VCCQ.
Then the poweroff_notify will be issued and fail. Instead sleep should
be issued.
Again, a "mmc_card_can_poweroff_notify" would be useful here.
> + } 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 +1418,11 @@ 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 +1480,7 @@ 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 +1492,7 @@ 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 0707d22..986e22b 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;
Kind regards
Ulf Hansson
next prev parent reply other threads:[~2012-04-30 8:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-30 6:14 [PATCH V2] MMC-4.5 Power OFF Notify rework Girish K S
2012-04-30 8:39 ` Ulf Hansson [this message]
2012-04-30 17:46 ` Saugata Das
2012-05-01 7:01 ` Subhash Jadavani
2012-04-30 13:09 ` Subhash Jadavani
2012-04-30 18:14 ` Saugata Das
2012-05-01 10:41 ` Girish K S
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