1 files changed, 33 insertions, 2 deletions

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index d13fb1d31821..217c1a0f8940 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1606,7 +1606,14 @@ static int macb_poll(struct napi_struct *napi, int budget)
 	if (work_done < budget) {
 		napi_complete_done(napi, work_done);
 
-		/* Packets received while interrupts were disabled */
+		/* RSR bits only seem to propagate to raise interrupts when
+		 * interrupts are enabled at the time, so if bits are already
+		 * set due to packets received while interrupts were disabled,
+		 * they will not cause another interrupt to be generated when
+		 * interrupts are re-enabled.
+		 * Check for this case here. This has been seen to happen
+		 * around 30% of the time under heavy network load.
+		 */
 		status = macb_readl(bp, RSR);
 		if (status) {
 			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
@@ -1614,6 +1621,22 @@ static int macb_poll(struct napi_struct *napi, int budget)
 			napi_reschedule(napi);
 		} else {
 			queue_writel(queue, IER, bp->rx_intr_mask);
+
+			/* In rare cases, packets could have been received in
+			 * the window between the check above and re-enabling
+			 * interrupts. Therefore, a double-check is required
+			 * to avoid losing a wakeup. This can potentially race
+			 * with the interrupt handler doing the same actions
+			 * if an interrupt is raised just after enabling them,
+			 * but this should be harmless.
+			 */
+			status = macb_readl(bp, RSR);
+			if (unlikely(status)) {
+				queue_writel(queue, IDR, bp->rx_intr_mask);
+				if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
+					queue_writel(queue, ISR, MACB_BIT(RCOMP));
+				napi_schedule(napi);
+			}
 		}
 	}
 
@@ -1666,6 +1689,7 @@ static void macb_tx_restart(struct macb_queue *queue)
 	unsigned int head = queue->tx_head;
 	unsigned int tail = queue->tx_tail;
 	struct macb *bp = queue->bp;
+	unsigned int head_idx, tbqp;
 
 	if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
 		queue_writel(queue, ISR, MACB_BIT(TXUBR));
@@ -1673,6 +1697,13 @@ static void macb_tx_restart(struct macb_queue *queue)
 	if (head == tail)
 		return;
 
+	tbqp = queue_readl(queue, TBQP) / macb_dma_desc_get_size(bp);
+	tbqp = macb_adj_dma_desc_idx(bp, macb_tx_ring_wrap(bp, tbqp));
+	head_idx = macb_adj_dma_desc_idx(bp, macb_tx_ring_wrap(bp, head));
+
+	if (tbqp == head_idx)
+		return;
+
 	macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
 }
 
@@ -4739,7 +4770,7 @@ static int macb_probe(struct platform_device *pdev)
 
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 	if (GEM_BFEXT(DAW64, gem_readl(bp, DCFG6))) {
-		dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
+		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(44));
 		bp->hw_dma_cap |= HW_DMA_CAP_64B;
 	}
 #endif