spi/fsl_espi: fix wrong setting of the address in the command buffer

Or else we can't operate on the right address when the trans length
is greater than 65535.
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/spi_fsl_espi.c

@@ -258,18 +258,18 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 	return mpc8xxx_spi->count;
 }
 
-static void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
+static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
 {
-	if (cmd[1] && cmd[2] && cmd[3]) {
+	if (cmd) {
 		cmd[1] = (u8)(addr >> 16);
 		cmd[2] = (u8)(addr >> 8);
 		cmd[3] = (u8)(addr >> 0);
 	}
 }
 
-static unsigned int fsl_espi_cmd2addr(u8 *cmd)
+static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
 {
-	if (cmd[1] && cmd[2] && cmd[3])
+	if (cmd)
 		return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
 
 	return 0;
@@ -395,9 +395,11 @@ static void fsl_espi_rw_trans(struct spi_message *m,
 			}
 		}
 
-		addr = fsl_espi_cmd2addr(local_buf);
-		addr += pos;
-		fsl_espi_addr2cmd(addr, local_buf);
+		if (pos > 0) {
+			addr = fsl_espi_cmd2addr(local_buf);
+			addr += pos;
+			fsl_espi_addr2cmd(addr, local_buf);
+		}
 
 		espi_trans->n_tx = n_tx;
 		espi_trans->n_rx = trans_len;