Re: [PATCH V2 2/2] mmc: block: Enable runtime pm for mmc blkdevice

[merez@codeaurora.org]

> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> Once the mmc blkdevice is being probed, runtime pm will be enabled.
> By using runtime autosuspend, the power save operations can be done
> when request inactivity occurs for a certain time. Right now the
> selected timeout value is set to 3 s.
>
> Moreover, when the blk device is being suspended, we make sure the device
> will be runtime resumed. The reason for doing this is that we what the
> host suspend sequence to be unaware of any runtime power save operations,
> so it can just handle the suspend as the device is fully powerered from a
powered
> runtime perspective.
>
> This patch is preparing to make it possible to move BKOPS handling into
> the runtime callbacks for the mmc bus_ops. Thus IDLE BKOPS can be
> accomplished.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Acked-by: Maya Erez <merez@codeaurora.org>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Acked-by: Kevin Liu <kliu5@marvell.com>
> ---
>  drivers/mmc/card/block.c |   28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index e12a03c..536331a 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -34,6 +34,7 @@
>  #include <linux/delay.h>
>  #include <linux/capability.h>
>  #include <linux/compat.h>
> +#include <linux/pm_runtime.h>
>
>  #include <linux/mmc/ioctl.h>
>  #include <linux/mmc/card.h>
> @@ -222,6 +223,7 @@ static ssize_t power_ro_lock_store(struct device *dev,
>  	md = mmc_blk_get(dev_to_disk(dev));
>  	card = md->queue.card;
>
> +	pm_runtime_get_sync(&card->dev);
>  	mmc_claim_host(card->host);
>
>  	ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP,
> @@ -234,6 +236,8 @@ static ssize_t power_ro_lock_store(struct device *dev,
>  		card->ext_csd.boot_ro_lock |= EXT_CSD_BOOT_WP_B_PWR_WP_EN;
>
>  	mmc_release_host(card->host);
> +	pm_runtime_mark_last_busy(&card->dev);
> +	pm_runtime_put_autosuspend(&card->dev);
>
>  	if (!ret) {
>  		pr_info("%s: Locking boot partition ro until next power on\n",
> @@ -492,6 +496,7 @@ static int mmc_blk_ioctl_cmd(struct block_device
> *bdev,
>
>  	mrq.cmd = &cmd;
>
> +	pm_runtime_get_sync(&card->dev);
>  	mmc_claim_host(card->host);
>
>  	err = mmc_blk_part_switch(card, md);
> @@ -560,6 +565,8 @@ static int mmc_blk_ioctl_cmd(struct block_device
> *bdev,
>
>  cmd_rel_host:
>  	mmc_release_host(card->host);
> +	pm_runtime_mark_last_busy(&card->dev);
> +	pm_runtime_put_autosuspend(&card->dev);
>
>  cmd_done:
>  	mmc_blk_put(md);
> @@ -1894,9 +1901,11 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq,
> struct request *req)
>  	struct mmc_host *host = card->host;
>  	unsigned long flags;
>
> -	if (req && !mq->mqrq_prev->req)
> +	if (req && !mq->mqrq_prev->req) {
> +		pm_runtime_get_sync(&card->dev);
>  		/* claim host only for the first request */
>  		mmc_claim_host(card->host);
> +	}
>
>  	ret = mmc_blk_part_switch(card, md);
>  	if (ret) {
> @@ -1933,7 +1942,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq,
> struct request *req)
>
>  out:
>  	if ((!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) ||
> -	     (req && (req->cmd_flags & MMC_REQ_SPECIAL_MASK)))
> +	     (req && (req->cmd_flags & MMC_REQ_SPECIAL_MASK))) {
>  		/*
>  		 * Release host when there are no more requests
>  		 * and after special request(discard, flush) is done.
> @@ -1941,6 +1950,10 @@ out:
>  		 * the 'mmc_blk_issue_rq' with 'mqrq_prev->req'.
>  		 */
>  		mmc_release_host(card->host);
> +		pm_runtime_mark_last_busy(&card->dev);
> +		pm_runtime_put_autosuspend(&card->dev);
> +	}
> +
>  	return ret;
>  }
>
> @@ -2337,6 +2350,12 @@ static int mmc_blk_probe(struct mmc_card *card)
>  		if (mmc_add_disk(part_md))
>  			goto out;
>  	}
> +
> +	pm_runtime_set_active(&card->dev);
> +	pm_runtime_set_autosuspend_delay(&card->dev, 3000);
> +	pm_runtime_use_autosuspend(&card->dev);
> +	pm_runtime_enable(&card->dev);
> +
>  	return 0;
>
>   out:
> @@ -2350,9 +2369,12 @@ static void mmc_blk_remove(struct mmc_card *card)
>  	struct mmc_blk_data *md = mmc_get_drvdata(card);
>
>  	mmc_blk_remove_parts(card, md);
> +	pm_runtime_get_sync(&card->dev);
>  	mmc_claim_host(card->host);
>  	mmc_blk_part_switch(card, md);
>  	mmc_release_host(card->host);
> +	pm_runtime_disable(&card->dev);
> +	pm_runtime_put_noidle(&card->dev);
>  	mmc_blk_remove_req(md);
>  	mmc_set_drvdata(card, NULL);
>  }
> @@ -2364,6 +2386,7 @@ static int mmc_blk_suspend(struct mmc_card *card)
>  	struct mmc_blk_data *md = mmc_get_drvdata(card);
>
>  	if (md) {
> +		pm_runtime_get_sync(&card->dev);
>  		mmc_queue_suspend(&md->queue);
>  		list_for_each_entry(part_md, &md->part, part) {
>  			mmc_queue_suspend(&part_md->queue);
> @@ -2387,6 +2410,7 @@ static int mmc_blk_resume(struct mmc_card *card)
>  		list_for_each_entry(part_md, &md->part, part) {
>  			mmc_queue_resume(&part_md->queue);
>  		}
> +		pm_runtime_put(&card->dev);
>  	}
>  	return 0;
>  }
> --
> 1.7.10
>
> --
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-- 
Maya Erez
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation