diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 393a1b077746..16e8db00fc49 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -431,12 +431,12 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host,
 {
 	int sg_count;
 
-	if (data->host_cookie == COOKIE_MAPPED) {
-		data->host_cookie = COOKIE_GIVEN;
+	/*
+	 * If the data buffers are already mapped, return the previous
+	 * dma_map_sg() result.
+	 */
+	if (data->host_cookie == COOKIE_PRE_MAPPED)
 		return data->sg_count;
-	}
-
-	WARN_ON(data->host_cookie == COOKIE_GIVEN);
 
 	sg_count = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
 				data->flags & MMC_DATA_WRITE ?
@@ -2094,7 +2094,7 @@ static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
 	mrq->data->host_cookie = COOKIE_UNMAPPED;
 
 	if (host->flags & SDHCI_REQ_USE_DMA)
-		sdhci_pre_dma_transfer(host, mrq->data, COOKIE_MAPPED);
+		sdhci_pre_dma_transfer(host, mrq->data, COOKIE_PRE_MAPPED);
 }
 
 static void sdhci_card_event(struct mmc_host *mmc)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0115e9907bf8..3bd28033dbd9 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -316,8 +316,8 @@ struct sdhci_adma2_64_desc {
 
 enum sdhci_cookie {
 	COOKIE_UNMAPPED,
-	COOKIE_MAPPED,
-	COOKIE_GIVEN,
+	COOKIE_PRE_MAPPED,	/* mapped by sdhci_pre_req() */
+	COOKIE_MAPPED,		/* mapped by sdhci_prepare_data() */
 };
 
 struct sdhci_host {