dmaengine: xilinx: dpdma: Limit descriptor IDs to 16 bits

While the descriptor ID is stored in a 32-bit field in the hardware
descriptor, only 16 bits are used by the hardware and are reported
through the XILINX_DPDMA_CH_DESC_ID register. Failure to handle the
wrap-around results in a descriptor ID mismatch after 65536 frames. Fix
it.

Signed-off-by: Laurent Pinchart <[email protected]>
Tested-by: Jianqiang Chen <[email protected]>
Reviewed-by: Jianqiang Chen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: pinchartl

drivers/dma/xilinx/xilinx_dpdma.c

@@ -113,6 +113,7 @@
 #define XILINX_DPDMA_CH_VDO				0x020
 #define XILINX_DPDMA_CH_PYLD_SZ				0x024
 #define XILINX_DPDMA_CH_DESC_ID				0x028
+#define XILINX_DPDMA_CH_DESC_ID_MASK			GENMASK(15, 0)
 
 /* DPDMA descriptor fields */
 #define XILINX_DPDMA_DESC_CONTROL_PREEMBLE		0xa5
@@ -866,7 +867,8 @@ static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
 	 * will be used, but it should be enough.
 	 */
 	list_for_each_entry(sw_desc, &desc->descriptors, node)
-		sw_desc->hw.desc_id = desc->vdesc.tx.cookie;
+		sw_desc->hw.desc_id = desc->vdesc.tx.cookie
+				    & XILINX_DPDMA_CH_DESC_ID_MASK;
 
 	sw_desc = list_first_entry(&desc->descriptors,
 				   struct xilinx_dpdma_sw_desc, node);
@@ -1086,7 +1088,8 @@ static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
 	if (!chan->running || !pending)
 		goto out;
 
-	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID);
+	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID)
+		& XILINX_DPDMA_CH_DESC_ID_MASK;
 
 	/* If the retrigger raced with vsync, retry at the next frame. */
 	sw_desc = list_first_entry(&pending->descriptors,