Blackfin arch: Add option to priorize DMA over Core

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

arch/blackfin/kernel/bfin_dma_5xx.c

@@ -73,6 +73,11 @@ static int __init blackfin_dma_init(void)
 	/* Mark MEMDMA Channel 0 as requested since we're using it internally */
 	dma_ch[CH_MEM_STREAM0_DEST].chan_status = DMA_CHANNEL_REQUESTED;
 	dma_ch[CH_MEM_STREAM0_SRC].chan_status = DMA_CHANNEL_REQUESTED;
+
+#if defined(CONFIG_DEB_DMA_URGENT)
+	bfin_write_EBIU_DDRQUE(bfin_read_EBIU_DDRQUE()
+			 | DEB1_URGENT | DEB2_URGENT | DEB3_URGENT);
+#endif
 	return 0;
 }
 

arch/blackfin/mach-bf548/Kconfig

@@ -2,6 +2,13 @@ if (BF54x)
 
 menu "BF548 Specific Configuration"
 
+config DEB_DMA_URGENT
+	bool "DMA has priority over core for ext. accesses"
+	depends on BF54x
+	default n
+	help
+	  Treat any DEB1, DEB2 and DEB3 request as Urgent
+
 comment "Interrupt Priority Assignment"
 menu "Priority"