staging: mt7621-mmc: Start cleanup of msdc_dma_config

Currently the msdc_dma_config function has some variables, that are
not needed, uses the macro msdc_init_bd that is only used here and
does not use the for_each_sg iterator. That last fact could cause a
bug if the scatterlist is chained.

The function is changed to remove these things, but none of the
changes should change the behavior of it (despite the case of a linked
scatterlist).

Signed-off-by: Christian Lütke-Stetzkamp <christian@lkamp.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index e25aeede7059f4a3369d27bb868b99733af1fb84..9c800a0b82068f02c9dec3c1faa81c92d70eddec 100644 (file)
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -209,15 +209,6 @@ static int msdc_rsp[] = {
                ((struct gpd *)_gpd)->blknum = blknum;      \
        } while (0)
 
-#define msdc_init_bd(_bd, blkpad, dwpad, dptr, dlen) \
-       do {                                        \
-               BUG_ON(dlen > 0xFFFFUL);            \
-               ((struct bd *)_bd)->blkpad = blkpad;        \
-               ((struct bd *)_bd)->dwpad  = dwpad;         \
-               ((struct bd *)_bd)->ptr    = (void *)dptr;  \
-               ((struct bd *)_bd)->buflen = dlen;          \
-       } while (0)
-
 #define msdc_txfifocnt()   ((sdr_read32(MSDC_FIFOCS) & MSDC_FIFOCS_TXCNT) >> 16)
 #define msdc_rxfifocnt()   ((sdr_read32(MSDC_FIFOCS) & MSDC_FIFOCS_RXCNT) >> 0)
 #define msdc_fifo_write32(v)   sdr_write32(MSDC_TXDATA, (v))
@@ -1260,9 +1251,8 @@ static u8 msdc_dma_calcs(u8 *buf, u32 len)
 static int msdc_dma_config(struct msdc_host *host, struct msdc_dma *dma)
 {
        u32 base = host->base;
-       u32 sglen = dma->sglen;
        //u32 i, j, num, bdlen, arg, xfersz;
-       u32 j, num, bdlen;
+       u32 j, num;
        u8  blkpad, dwpad, chksum;
        struct scatterlist *sg = dma->sg;
        struct gpd *gpd;
@@ -1291,12 +1281,11 @@ static int msdc_dma_config(struct msdc_host *host, struct msdc_dma *dma)
                chksum = (dma->flags & DMA_FLAG_EN_CHKSUM) ? 1 : 0;
 
                /* calculate the required number of gpd */
-               num = (sglen + MAX_BD_PER_GPD - 1) / MAX_BD_PER_GPD;
+               num = (dma->sglen + MAX_BD_PER_GPD - 1) / MAX_BD_PER_GPD;
                BUG_ON(num != 1);
 
                gpd = dma->gpd;
                bd  = dma->bd;
-               bdlen = sglen;
 
                /* modify gpd*/
                //gpd->intr = 0;
@@ -1306,19 +1295,23 @@ static int msdc_dma_config(struct msdc_host *host, struct msdc_dma *dma)
                gpd->chksum = (chksum ? msdc_dma_calcs((u8 *)gpd, 16) : 0);
 
                /* modify bd*/
-               for (j = 0; j < bdlen; j++) {
-                       msdc_init_bd(&bd[j], blkpad, dwpad, sg_dma_address(sg), sg_dma_len(sg));
-                       if (j == bdlen - 1)
+               for_each_sg(dma->sg, sg, dma->sglen, j) {
+                       bd[j].blkpad = blkpad;
+                       bd[j].dwpad = dwpad;
+                       bd[j].ptr = (void *)sg_dma_address(sg);
+                       bd[j].buflen = sg_dma_len(sg);
+
+                       if (j == dma->sglen - 1)
                                bd[j].eol = 1;  /* the last bd */
                        else
                                bd[j].eol = 0;
+
                        bd[j].chksum = 0; /* checksume need to clear first */
                        bd[j].chksum = (chksum ? msdc_dma_calcs((u8 *)(&bd[j]), 16) : 0);
-                       sg++;
                }
 
                dma->used_gpd += 2;
-               dma->used_bd += bdlen;
+               dma->used_bd += dma->sglen;
 
                sdr_set_field(MSDC_DMA_CFG, MSDC_DMA_CFG_DECSEN, chksum);
                sdr_set_field(MSDC_DMA_CTRL, MSDC_DMA_CTRL_BRUSTSZ,