drivers: mtd: nand: cadence: Flush & invalidate dma descriptor

Ensure ddr memory is updated with the data from dcache.
This would help to ensure cdma always reading the latest dma descriptor
from ddr memory.

Signed-off-by: Dinesh Maniyam <dinesh.maniyam@intel.com>
diff --git a/drivers/mtd/nand/raw/cadence_nand.c b/drivers/mtd/nand/raw/cadence_nand.c
index 71bab97..a717987 100644
--- a/drivers/mtd/nand/raw/cadence_nand.c
+++ b/drivers/mtd/nand/raw/cadence_nand.c
@@ -430,6 +430,10 @@
 
 	cdma_desc->command_type = ctype;
 	cdma_desc->ctrl_data_ptr = ctrl_data_ptr;
+
+	flush_cache((dma_addr_t)cadence->cdma_desc,
+		    ROUND(sizeof(struct cadence_nand_cdma_desc),
+			  ARCH_DMA_MINALIGN));
 }
 
 static u8 cadence_nand_check_desc_error(struct cadence_nand_info *cadence,
@@ -457,6 +461,11 @@
 	struct cadence_nand_cdma_desc *desc_ptr = cadence->cdma_desc;
 	u8 status = STAT_BUSY;
 
+	invalidate_dcache_range((dma_addr_t)cadence->cdma_desc,
+				(dma_addr_t)cadence->cdma_desc +
+				ROUND(sizeof(struct cadence_nand_cdma_desc),
+				      ARCH_DMA_MINALIGN));
+
 	if (desc_ptr->status & CDMA_CS_FAIL) {
 		status = cadence_nand_check_desc_error(cadence,
 						       desc_ptr->status);