mmc: dw_mmc: use the cookie's enum values for post/pre_req()

This patch removed the meaningless value. Instead, use the cookie's enum
values for executing correctly.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

2 files changed, 25 insertions, 20 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 0b220e5a8169..65546b6df840 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -414,12 +414,13 @@ static void dw_mci_dma_cleanup(struct dw_mci *host)
 {
         struct mmc_data *data = host->data;
 
-        if (data)
-                if (!data->host_cookie)
-                        dma_unmap_sg(host->dev,
-                                     data->sg,
-                                     data->sg_len,
-                                     dw_mci_get_dma_dir(data));
+        if (data && data->host_cookie == COOKIE_MAPPED) {
+                dma_unmap_sg(host->dev,
+                             data->sg,
+                             data->sg_len,
+                             dw_mci_get_dma_dir(data));
+                data->host_cookie = COOKIE_UNMAPPED;
+        }
 }
 
 static void dw_mci_idmac_reset(struct dw_mci *host)
@@ -850,13 +851,13 @@ static const struct dw_mci_dma_ops dw_mci_edmac_ops = {
 
 static int dw_mci_pre_dma_transfer(struct dw_mci *host,
                                    struct mmc_data *data,
-                                   bool next)
+                                   int cookie)
 {
         struct scatterlist *sg;
         unsigned int i, sg_len;
 
-        if (!next && data->host_cookie)
-                return data->host_cookie;
+        if (data->host_cookie == COOKIE_PRE_MAPPED)
+                return data->sg_len;
 
         /*
          * We don't do DMA on "complex" transfers, i.e. with
@@ -881,8 +882,7 @@ static int dw_mci_pre_dma_transfer(struct dw_mci *host,
         if (sg_len == 0)
                 return -EINVAL;
 
-        if (next)
-                data->host_cookie = sg_len;
+        data->host_cookie = cookie;
 
         return sg_len;
 }
@@ -897,13 +897,12 @@ static void dw_mci_pre_req(struct mmc_host *mmc,
         if (!slot->host->use_dma || !data)
                 return;
 
-        if (data->host_cookie) {
-                data->host_cookie = 0;
-                return;
-        }
+        /* This data might be unmapped at this time */
+        data->host_cookie = COOKIE_UNMAPPED;
 
-        if (dw_mci_pre_dma_transfer(slot->host, mrq->data, 1) < 0)
-                data->host_cookie = 0;
+        if (dw_mci_pre_dma_transfer(slot->host, mrq->data,
+                                COOKIE_PRE_MAPPED) < 0)
+                data->host_cookie = COOKIE_UNMAPPED;
 }
 
 static void dw_mci_post_req(struct mmc_host *mmc,
@@ -916,12 +915,12 @@ static void dw_mci_post_req(struct mmc_host *mmc,
         if (!slot->host->use_dma || !data)
                 return;
 
-        if (data->host_cookie)
+        if (data->host_cookie != COOKIE_UNMAPPED)
                 dma_unmap_sg(slot->host->dev,
                              data->sg,
                              data->sg_len,
                              dw_mci_get_dma_dir(data));
-        data->host_cookie = 0;
+        data->host_cookie = COOKIE_UNMAPPED;
 }
 
 static void dw_mci_adjust_fifoth(struct dw_mci *host, struct mmc_data *data)
@@ -1027,7 +1026,7 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
         if (!host->use_dma)
                 return -ENODEV;
 
-        sg_len = dw_mci_pre_dma_transfer(host, data, 0);
+        sg_len = dw_mci_pre_dma_transfer(host, data, COOKIE_MAPPED);
         if (sg_len < 0) {
                 host->dma_ops->stop(host);
                 return sg_len;
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index f5af2bd35e7f..15db6f83f53f 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -39,6 +39,12 @@ enum {
         EVENT_DATA_ERROR,
 };
 
+enum dw_mci_cookie {
+        COOKIE_UNMAPPED,
+        COOKIE_PRE_MAPPED,      /* mapped by pre_req() of dwmmc */
+        COOKIE_MAPPED,          /* mapped by prepare_data() of dwmmc */
+};
+
 struct mmc_data;
 
 enum {