Re: [PATCH v2] mmc: core: eMMC in Sleep mode before suspend

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On 09/09/11 09:34, Subhash Jadavani wrote:
Hi Balaji,

Put MMC to sleep if it supports SLEEP/AWAKE (CMD5)
in the mmc suspend so that Vcc (NAND core) can be cut
to minimize power consumption.
eMMC put into SLEEP can respond to CMD0 or H/W reset or CMD5.
Current implemention on resume from suspend relies on CMD0 in
mmc_init_card to get out of SLEEP mode.

Signed-off-by: Balaji T K<balajitk@xxxxxx>
Acked-by: Venkatraman S<svenkatr@xxxxxx>
---
  drivers/mmc/core/mmc.c |    9 +++++++--
  1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 5700b1c..f73fcee 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -553,6 +553,7 @@ static int mmc_init_card(struct mmc_host *host, u32
ocr,
  	 * need to tell some cards to go back to the idle
  	 * state.  We wait 1ms to give cards time to
  	 * respond.
+	 * mmc_go_idle is needed for eMMC that are asleep
  	 */
  	mmc_go_idle(host);

@@ -900,16 +901,20 @@ static void mmc_detect(struct mmc_host *host)
   */
  static int mmc_suspend(struct mmc_host *host)
  {
+	int err = 0;
+
  	BUG_ON(!host);
  	BUG_ON(!host->card);

  	mmc_claim_host(host);
-	if (!mmc_host_is_spi(host))
+	if (mmc_card_can_sleep(host))
+		err = mmc_card_sleep(host);
+	else if (!mmc_host_is_spi(host))
  		mmc_deselect_cards(host);
  	host->card->state&= ~MMC_STATE_HIGHSPEED;
  	mmc_release_host(host);

-	return 0;
+	return err;
  }

Looks good to me:
Reviewed-by: Subhash Jadavani<subhashj@xxxxxxxxxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>


Thanks,
Subhash


  /*
--
1.7.0.4





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