Change emac completion detection to interrupt

Changing the emac software to monitor for an interrupt assertion
triggered from the last RX descriptor to indicate that the data movement
is complete. The original method of waiting for the DMA to indicate it
had exhausted all TX and RX descriptors was not working reliably on the
Critical Link board.

Signed-off-by: Rod Frazer <rod.frazer@intel.com>

Author: rodfrazer-intel

common_sw/linux_apps/emac.c

@@ -451,6 +451,9 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac,
 		rx_descriptors[i].desc3 = 0x80000000;
 	}
 
+	/* enable interrupt from last RX descriptor */
+	rx_descriptors[i-1].desc3 |= 0x40000000;
+
 	/* null the last tx descriptor in the ring */
 	tx_descriptors[i].desc0 = 0;
 	tx_descriptors[i].desc1 = 0;
@@ -607,7 +610,7 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac,
 
 	temp_32 = *((volatile uint32_t *)(emac_uio_map->uio_mmap_addr +
 		((EMAC0_DMA_CH0_BASE + DMA_CH0_Status_OFST) & 0x3FFF)));
-	while(temp_32 != 0x00000084) {
+	while((temp_32 & 0x00000040) == 0) {
 		asm volatile (
 			"mrs %[temp], cntvct_el0\n"
 			: [temp] "=r" (temp)

common_sw/u-boot_standalone_apps/emac.c

@@ -293,6 +293,9 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac) {
 		rx_descriptors[i].desc3 = 0x80000000;
 	}
 
+	/* enable interrupt from last RX descriptor */
+	rx_descriptors[i-1].desc3 |= 0x40000000;
+
 	/* null the last tx descriptor in the ring */
 	tx_descriptors[i].desc0 = 0;
 	tx_descriptors[i].desc1 = 0;
@@ -481,7 +484,7 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac) {
 
 	temp_32 = *((volatile uint32_t *)(EMAC0_DMA_CH0_BASE +
 							DMA_CH0_Status_OFST));
-	while(temp_32 != 0x00000084) {
+	while((temp_32 & 0x00000040) == 0) {
 		asm volatile (
 			"mrs %[temp], cntpct_el0\n"
 			: [temp] "=r" (temp)
@@ -601,6 +604,9 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac) {
 		rx_descriptors[i].desc3 = 0x80000000;
 	}
 
+	/* enable interrupt from last RX descriptor */
+	rx_descriptors[i-1].desc3 |= 0x40000000;
+
 	/* null the last tx descriptor in the ring */
 	tx_descriptors[i].desc0 = 0;
 	tx_descriptors[i].desc1 = 0;
@@ -789,7 +795,7 @@ void do_the_interesting_thing(struct hps_emac_s *hps_emac) {
 
 	temp_32 = *((volatile uint32_t *)(EMAC0_DMA_CH0_BASE +
 							DMA_CH0_Status_OFST));
-	while(temp_32 != 0x00000084) {
+	while((temp_32 & 0x00000040) == 0) {
 		asm volatile (
 			"mrs %[temp], cntpct_el0\n"
 			: [temp] "=r" (temp)