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>
diff --git a/drivers/mmc/card/Kconfig b/drivers/mmc/card/Kconfig
index 3b1f783..ebb4afe 100644
--- a/drivers/mmc/card/Kconfig
+++ b/drivers/mmc/card/Kconfig
@@ -50,6 +50,15 @@
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 0227e13..697c223 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1379,12 +1379,22 @@
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);
@@ -1771,6 +1781,9 @@
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;
@@ -1796,6 +1809,9 @@
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
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 3aad3dc..4db6bc1 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2050,6 +2050,12 @@
host->detect_change = 0;
+ /* If the card was removed the bus will be marked
+ * as dead - extend the wakelock so userspace
+ * can respond */
+ if (host->bus_dead)
+ extend_wakelock = 1;
+
/*
* Let mmc_bus_put() free the bus/bus_ops if we've found that
* the card is no longer present.