dmaengine: pl330: Limit MFIFO usage for memcpy to avoid exhausting entries

The MFIFO is shared by all channels so restrict each memcpy to it's fair
share. This is being over cautious, but without a global view of DMA
channel usage on a system it's not possible to come up with a more
optimum safe limit.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/pl330.c

@@ -2336,7 +2336,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
 	int burst_len;
 
 	burst_len = pl330->pcfg.data_bus_width / 8;
-	burst_len *= pl330->pcfg.data_buf_dep;
+	burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan;
 	burst_len >>= desc->rqcfg.brst_size;
 
 	/* src/dst_burst_len can't be more than 16 */