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authorSan Mehat <san@google.com>2009-07-30 08:21:19 -0700
committerDan Willemsen <dwillemsen@nvidia.com>2011-11-30 21:37:58 -0800
commitcc106cbdc4ea09836ad07a1988cc4d0edf74a48a (patch)
treef0cc1c75e966418882e1459b14935254baa02578 /drivers/mmc/card
parentbeb9eb38c6eb46c3ba9028356c3abe8d2f62cafd (diff)
mmc: mmcblk: Add support for deferred SD bus resume
Signed-off-by: San Mehat <san@google.com> mmc: card: Add MMC_BLOCK_DEFERRED_RESUME option to Kconfig Signed-off-by: San Mehat <san@google.com>
Diffstat (limited to 'drivers/mmc/card')
-rw-r--r--drivers/mmc/card/Kconfig9
-rw-r--r--drivers/mmc/card/block.c18
2 files changed, 27 insertions, 0 deletions
diff --git a/drivers/mmc/card/Kconfig b/drivers/mmc/card/Kconfig
index 3b1f783bf924..ebb4afe6c702 100644
--- a/drivers/mmc/card/Kconfig
+++ b/drivers/mmc/card/Kconfig
@@ -50,6 +50,15 @@ config MMC_BLOCK_BOUNCE
If unsure, say Y here.
+config MMC_BLOCK_DEFERRED_RESUME
+ bool "Deferr MMC layer resume until I/O is requested"
+ depends on MMC_BLOCK
+ default n
+ help
+ Say Y here to enable deferred MMC resume until I/O
+ is requested. This will reduce overall resume latency and
+ save power when theres an SD card inserted but not being used.
+
config SDIO_UART
tristate "SDIO UART/GPS class support"
help
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 4c1a648d00fc..a2136d4dc672 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1178,12 +1178,22 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
return 0;
}
+static int
+mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card);
+
static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
int ret;
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
+#ifdef CONFIG_MMC_BLOCK_DEFERRED_RESUME
+ if (mmc_bus_needs_resume(card->host)) {
+ mmc_resume_bus(card->host);
+ mmc_blk_set_blksize(md, card);
+ }
+#endif
+
if (req && !mq->mqrq_prev->req)
/* claim host only for the first request */
mmc_claim_host(card->host);
@@ -1527,6 +1537,9 @@ static int mmc_blk_probe(struct mmc_card *card)
mmc_set_drvdata(card, md);
mmc_fixup_device(card, blk_fixups);
+#ifdef CONFIG_MMC_BLOCK_DEFERRED_RESUME
+ mmc_set_bus_resume_policy(card->host, 1);
+#endif
if (mmc_add_disk(md))
goto out;
@@ -1552,6 +1565,9 @@ static void mmc_blk_remove(struct mmc_card *card)
mmc_release_host(card->host);
mmc_blk_remove_req(md);
mmc_set_drvdata(card, NULL);
+#ifdef CONFIG_MMC_BLOCK_DEFERRED_RESUME
+ mmc_set_bus_resume_policy(card->host, 0);
+#endif
}
#ifdef CONFIG_PM
@@ -1575,7 +1591,9 @@ static int mmc_blk_resume(struct mmc_card *card)
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
+#ifndef CONFIG_MMC_BLOCK_DEFERRED_RESUME
mmc_blk_set_blksize(md, card);
+#endif
/*
* Resume involves the card going into idle state,