mmc: dw_mmc: fix the spamming log message

When there is no Card which is set to "broken-cd", it's displayed a clock
information continuously. Because it's polling for detecting card.
This patch is fixed this problem.

Fixes: 65257a0d ("mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()")
Reported-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.c

@@ -1112,11 +1112,12 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
 
 		div = (host->bus_hz != clock) ? DIV_ROUND_UP(div, 2) : 0;
 
-		dev_info(&slot->mmc->class_dev,
-			 "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n",
-			 slot->id, host->bus_hz, clock,
-			 div ? ((host->bus_hz / div) >> 1) :
-			 host->bus_hz, div);
+		if (clock != slot->__clk_old || force_clkinit)
+			dev_info(&slot->mmc->class_dev,
+				 "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n",
+				 slot->id, host->bus_hz, clock,
+				 div ? ((host->bus_hz / div) >> 1) :
+				 host->bus_hz, div);
 
 		/* disable clock */
 		mci_writel(host, CLKENA, 0);
@@ -1139,6 +1140,9 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
 
 		/* inform CIU */
 		mci_send_cmd(slot, sdmmc_cmd_bits, 0);
+
+		/* keep the last clock value that was requested from core */
+		slot->__clk_old = clock;
 	}
 
 	host->current_speed = clock;

drivers/mmc/host/dw_mmc.h

@@ -249,6 +249,8 @@ extern int dw_mci_resume(struct dw_mci *host);
  * @queue_node: List node for placing this node in the @queue list of
  *	&struct dw_mci.
  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
+ * @__clk_old: The last clock value that was requested from core.
+ *	Keeping track of this helps us to avoid spamming the console.
  * @flags: Random state bits associated with the slot.
  * @id: Number of this slot.
  * @sdio_id: Number of this slot in the SDIO interrupt registers.
@@ -263,6 +265,7 @@ struct dw_mci_slot {
 	struct list_head	queue_node;
 
 	unsigned int		clock;
+	unsigned int		__clk_old;
 
 	unsigned long		flags;
 #define DW_MMC_CARD_PRESENT	0