Re: [RFC/PATCH] mmc: block: use block layer pm helpers for pm of card device

From: Konstantin Dorfman
Date: Wed Apr 29 2015 - 04:45:37 EST


Hello Ulf, Chris,

Now as rc1 is out and the patch format fixed, please look into it again.

Thanks,
Kostya

On 04/21/2015 05:20 PM, Konstantin Dorfman wrote:
Use of block layer runtime PM helpers, implementing the block layer's
request-based mechanism, simplifies data path of mmc core layer. It
enables to remove synchronous call pm_runtime_get_sync() from mmc core
data path.

The idea and API is designed by Alan Stern and described here:
http://marc.info/?l=linux-scsi&m=133727953625963&w=2

Signed-off-by: Konstantin Dorfman <kdorfman@xxxxxxxxxxxxxx>

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 1fa4c80..de5f85d 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -2017,7 +2017,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)

if (req && !mq->mqrq_prev->req)
/* claim host only for the first request */
- mmc_get_card(card);
+ mmc_claim_host(card->host);

ret = mmc_blk_part_switch(card, md);
if (ret) {
@@ -2060,7 +2060,7 @@ out:
* In case sepecial request, there is no reentry to
* the 'mmc_blk_issue_rq' with 'mqrq_prev->req'.
*/
- mmc_put_card(card);
+ mmc_release_host(card->host);
return ret;
}

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index feea926..e12c828 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -213,6 +213,11 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
if (mmc_can_erase(card))
mmc_queue_setup_discard(mq->queue, card);

+ if (!subname) {
+ blk_pm_runtime_init(mq->queue, &card->dev);
+ card->q = mq->queue;
+ }
+
#ifdef CONFIG_MMC_BLOCK_BOUNCE
if (host->max_segs == 1) {
unsigned int bouncesz;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index a301a78..bf3f919 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/pm_runtime.h>
+#include <linux/blkdev.h>

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
@@ -1814,11 +1815,17 @@ static int mmc_runtime_suspend(struct mmc_host *host)
if (!(host->caps & MMC_CAP_AGGRESSIVE_PM))
return 0;

+ err = blk_pre_runtime_suspend(host->card->q);
+ if (err)
+ return err;
+
err = _mmc_suspend(host, true);
if (err)
pr_err("%s: error %d doing aggessive suspend\n",
mmc_hostname(host), err);

+ blk_post_runtime_suspend(host->card->q, err);
+
return err;
}

@@ -1832,12 +1839,16 @@ static int mmc_runtime_resume(struct mmc_host *host)
if (!(host->caps & (MMC_CAP_AGGRESSIVE_PM | MMC_CAP_RUNTIME_RESUME)))
return 0;

+ blk_pre_runtime_resume(host->card->q);
+
err = _mmc_resume(host);
if (err)
pr_err("%s: error %d doing aggessive resume\n",
mmc_hostname(host), err);

- return 0;
+ blk_post_runtime_resume(host->card->q, err);
+
+ return err;
}

static int mmc_power_restore(struct mmc_host *host)
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index b0692d2..1f4810b 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -244,6 +244,7 @@ struct mmc_part {
struct mmc_card {
struct mmc_host *host; /* the host this device belongs to */
struct device dev; /* the device */
+ struct request_queue *q;
u32 ocr; /* the current OCR setting */
unsigned int rca; /* relative card address of device */
unsigned int type; /* card type */



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