On 14 October 2011 03:41, Chris Ball <[email protected]> wrote:
> Hi Girish, just trivial changes below.
>
> Does anyone have a Tested-by: to add to the patch?
No not yet.
>
> On Thu, Oct 13 2011, Girish K S wrote:
>> This patch adds the support for power off notify feature, available in
>> eMMC 4.5 devices. If the the host has support for this feature, then the
>> mmc core will notify it to the device by setting the POWER_OFF_NOTIFICATION
>> byte in the extended csd register with a value 1(POWER_ON).
>>
>> For suspend mode short timeout is used, whereas for the normal poweroff long
>> timeout is used.
>> cc: Chris Ball <[email protected]>
>> Signed-off-by: Girish K S <[email protected]>
>> Signed-off-by: Jaehoon Chung <[email protected]>
>> ---
>> Changes in V8:
>> Updated with review comments of Chris Ball and rebased to
>> chris-mmc/mmc-next branch.
>> Changes in V7:
>> Rebased to chris-mmc/mmc-next branch. merged to patches
>> to single patch.
>> Changes in V6:
>> Fixes checkpatch errors. The patches are generated after
>> rebasing to chris's mmc-next branch.
>> Changes in V5:
>> This patch version fixes the problem with power off
>> notify function, when called for the first time and
>> card is not yet initialised.
>> Changes in V4:
>> Updated with review comments of Jeon
>> Changes in V2:
>> Adds poweroff notification handling in suspend/normal.
>>
>> drivers/mmc/core/core.c | 36 ++++++++++++++++++++++++++++++++++++
>> drivers/mmc/core/mmc.c | 23 +++++++++++++++++++++--
>> drivers/mmc/host/sdhci.c | 9 +++++++++
>> include/linux/mmc/card.h | 6 ++++++
>> include/linux/mmc/host.h | 6 ++++++
>> include/linux/mmc/mmc.h | 8 ++++++++
>> 6 files changed, 86 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index 61d7730..db368b2 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -1212,11 +1212,45 @@ static void mmc_power_up(struct mmc_host *host)
>>
>> void mmc_power_off(struct mmc_host *host)
>> {
>> + struct mmc_card *card;
>
> struct mmc_card *card = host->card;
>
>> + unsigned int notify_type;
>> + unsigned int timeout;
>> + int err;
>> +
>> + BUG_ON(!host);
>
> Not necessary.
OK
>
>> +
>> mmc_host_clk_hold(host);
>>
>> + card = host->card;
>> host->ios.clock = 0;
>> host->ios.vdd = 0;
>>
>> + if (card != NULL && mmc_card_mmc(card) &&
>
> != NULL is unnecessary.
This is required. Let me explain the scenario where i felt it is necessary.
The card resource will be allocated when the delayed work is scheduled
i.e.(on invocation of the function mmc_rescan)
The call trace for card instance creation is given below in the called
sequence. mmc_rescan->mmc_rescan_try_freq->mmc_attach_mmc->mmc_init_card.
Before the above card resource is allocated, the power_off function is
invoked in the function mmc_start_host (invoked by the add_host)
At this point of time the card == NULL and system crashes. So i check
for NULL first and then the card state.
>
>> + (card->poweroff_notify_state == MMC_POWERED_ON)) {
>
> Extra set of parens unnecessary.
OK
>
>> +
>> + 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;
>> + }
>> +
>> /*
>> * Reset ocr mask to be the highest possible voltage supported for
>> * this mmc host. This value will be used at next power up.
>> @@ -2208,6 +2242,7 @@ 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);
>>
>> @@ -2231,6 +2266,7 @@ 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 4e869d3..f8ea938 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -458,10 +458,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8
>> *ext_csd)
>> else
>> card->erased_byte = 0x0;
>>
>> - if (card->ext_csd.rev >= 6)
>> + if (card->ext_csd.rev >= 6) {
>> card->ext_csd.generic_cmd6_time = 10 *
>> ext_csd[EXT_CSD_GENERIC_CMD6_TIME];
>> - else
>> + card->ext_csd.power_off_longtime = 10 *
>> + ext_csd[EXT_CSD_POWER_OFF_LONG_TIME];
>> + } else
>> card->ext_csd.generic_cmd6_time = 0;
>>
>> out:
>> @@ -846,6 +848,23 @@ 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->caps2 & MMC_CAP2_POWEROFF_NOTIFY) &&
>> + (card->poweroff_notify_state == MMC_NO_POWER_NOTIFICATION)) {
>> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> + EXT_CSD_POWER_OFF_NOTIFICATION,
>> + EXT_CSD_POWER_ON,
>> + card->ext_csd.generic_cmd6_time);
>> + if (err && err != -EBADMSG)
>> + goto free_card;
>> + }
>> +
>> + if (!err)
>> + card->poweroff_notify_state = MMC_POWERED_ON;
>> +
>> + /*
>> * Activate high speed (if supported)
>> */
>> if ((card->ext_csd.hs_max_dtr != 0) &&
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 2cc3ffa..91fdaed 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -2739,6 +2739,15 @@ 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 by the host, set notify to
>> + * short power off notify timeout value.
>> + */
>> + if (mmc->caps2 & MMC_CAP2_POWEROFF_NOTIFY)
>> + mmc->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
>> + else
>> + mmc->power_notify_type = MMC_HOST_PW_NOTIFY_NONE;
>> +
>> /* 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 30d493c..fce88b3 100644
>> --- a/include/linux/mmc/card.h
>> +++ b/include/linux/mmc/card.h
>> @@ -54,6 +54,7 @@ struct mmc_ext_csd {
>> unsigned int part_time; /* Units: ms */
>> unsigned int sa_timeout; /* Units: 100ns */
>> unsigned int generic_cmd6_time; /* Units: 10ms */
>> + unsigned int power_off_longtime; /* Units: ms */
>> unsigned int hs_max_dtr;
>> unsigned int sectors;
>> unsigned int card_type;
>> @@ -209,6 +210,11 @@ struct mmc_card {
>> #define MMC_QUIRK_BLK_NO_CMD23 (1<<7) /* Avoid CMD23 for
>> regular multiblock */
>> #define MMC_QUIRK_BROKEN_BYTE_MODE_512 (1<<8) /* Avoid sending 512
>> bytes in */
>> /* byte mode */
>> + 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 */
>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>> index aed5bc7..65c47fc 100644
>> --- a/include/linux/mmc/host.h
>> +++ b/include/linux/mmc/host.h
>> @@ -239,8 +239,14 @@ struct mmc_host {
>> unsigned int caps2; /* More host capabilities */
>>
>> #define MMC_CAP2_BOOTPART_NOACC (1 << 0) /* Boot partition no
>> access */
>> +#define MMC_CAP2_CACHE_CTRL (1 << 1) /* Allow cache control. */
>> +#define MMC_CAP2_POWEROFF_NOTIFY (1 << 2) /* Notify poweroff supported */
>>
>> mmc_pm_flag_t pm_caps; /* supported pm features */
>> + unsigned int power_notify_type;
>
> You can align "power_notify_type" alongside "pm_caps" here.
OK
>
> Thanks,
>
> - Chris.
> --
> Chris Ball <[email protected]> <http://printf.net/>
> One Laptop Per Child
>
Thanks for the comments. please let me know if something wrong with my
above justification. Or any alternative for the same
regards
Girish K S
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