mmc: core: Cleanup BKOPS support

It's been ~6 years ago since we introduced the BKOPS support for eMMC
cards. The current code is a bit messy and primarily that's because it
prepares to support running BKOPS in an asynchronous mode. However, that
mode has never been fully implemented/enabled. Instead BKOPS is always
executed in synchronously, when the card has reported an urgent BKOPS
level.

For these reasons, let's make the code more readable by dropping the unused
parts. Let's also rename mmc_start_bkops() to mmc_run_bkops(), as to make
it more descriptive.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 18 insertions, 69 deletions

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index ffc74d44ee67..9054329fe903 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -891,34 +891,6 @@ int mmc_can_ext_csd(struct mmc_card *card)
 	return (card && card->csd.mmca_vsn > CSD_SPEC_VER_3);
 }
 
-/**
- *	mmc_stop_bkops - stop ongoing BKOPS
- *	@card: MMC card to check BKOPS
- *
- *	Send HPI command to stop ongoing background operations to
- *	allow rapid servicing of foreground operations, e.g. read/
- *	writes. Wait until the card comes out of the programming state
- *	to avoid errors in servicing read/write requests.
- */
-int mmc_stop_bkops(struct mmc_card *card)
-{
-	int err = 0;
-
-	err = mmc_interrupt_hpi(card);
-
-	/*
-	 * If err is EINVAL, we can't issue an HPI.
-	 * It should complete the BKOPS.
-	 */
-	if (!err || (err == -EINVAL)) {
-		mmc_card_clr_doing_bkops(card);
-		mmc_retune_release(card->host);
-		err = 0;
-	}
-
-	return err;
-}
-
 static int mmc_read_bkops_status(struct mmc_card *card)
 {
 	int err;
@@ -935,22 +907,17 @@ static int mmc_read_bkops_status(struct mmc_card *card)
 }
 
 /**
- *	mmc_start_bkops - start BKOPS for supported cards
- *	@card: MMC card to start BKOPS
- *	@from_exception: A flag to indicate if this function was
- *			 called due to an exception raised by the card
+ *	mmc_run_bkops - Run BKOPS for supported cards
+ *	@card: MMC card to run BKOPS for
  *
- *	Start background operations whenever requested.
- *	When the urgent BKOPS bit is set in a R1 command response
- *	then background operations should be started immediately.
+ *	Run background operations synchronously for cards having manual BKOPS
+ *	enabled and in case it reports urgent BKOPS level.
 */
-void mmc_start_bkops(struct mmc_card *card, bool from_exception)
+void mmc_run_bkops(struct mmc_card *card)
 {
 	int err;
-	int timeout;
-	bool use_busy_signal;
 
-	if (!card->ext_csd.man_bkops_en || mmc_card_doing_bkops(card))
+	if (!card->ext_csd.man_bkops_en)
 		return;
 
 	err = mmc_read_bkops_status(card);
@@ -960,44 +927,26 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
 		return;
 	}
 
-	if (!card->ext_csd.raw_bkops_status)
+	if (!card->ext_csd.raw_bkops_status ||
+	    card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2)
 		return;
 
-	if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2 &&
-	    from_exception)
-		return;
-
-	if (card->ext_csd.raw_bkops_status >= EXT_CSD_BKOPS_LEVEL_2) {
-		timeout = MMC_OPS_TIMEOUT_MS;
-		use_busy_signal = true;
-	} else {
-		timeout = 0;
-		use_busy_signal = false;
-	}
-
 	mmc_retune_hold(card->host);
 
-	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-			EXT_CSD_BKOPS_START, 1, timeout, 0,
-			use_busy_signal, true, false);
-	if (err) {
+	/*
+	 * For urgent BKOPS status, LEVEL_2 and higher, let's execute
+	 * synchronously. Future wise, we may consider to start BKOPS, for less
+	 * urgent levels by using an asynchronous background task, when idle.
+	 */
+	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			EXT_CSD_BKOPS_START, 1, MMC_OPS_TIMEOUT_MS);
+	if (err)
 		pr_warn("%s: Error %d starting bkops\n",
 			mmc_hostname(card->host), err);
-		mmc_retune_release(card->host);
-		return;
-	}
 
-	/*
-	 * For urgent bkops status (LEVEL_2 and more)
-	 * bkops executed synchronously, otherwise
-	 * the operation is in progress
-	 */
-	if (!use_busy_signal)
-		mmc_card_set_doing_bkops(card);
-	else
-		mmc_retune_release(card->host);
+	mmc_retune_release(card->host);
 }
-EXPORT_SYMBOL(mmc_start_bkops);
+EXPORT_SYMBOL(mmc_run_bkops);
 
 /*
  * Flush the cache to the non-volatile storage.