[RFC PATCH 0/3] Miscellaneous fixes in macb driver

[RFC PATCH 0/3] Miscellaneous fixes in macb driver

[Harini Katakam]

This series fixes the following:
-> Ties off unused RX queues
-> Handles RX HRESP error

Edgar E. Iglesias (2):
  net: macb: Add RBQP to the macb queues
  net: macb: Tie-off unused RX queues

Harini Katakam (1):
  net: macb: Handle HRESP error

 drivers/net/ethernet/cadence/macb.h      |   5 ++
 drivers/net/ethernet/cadence/macb_main.c | 109 +++++++++++++++++++++++++++++--
 2 files changed, 110 insertions(+), 4 deletions(-)

-- 
2.7.4

[RFC PATCH 1/3] net: macb: Add RBQP to the macb queues

[Harini Katakam]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Add RX queue pointer to macb queues to make it accessible for the
multiple queues available. Currently the first RX queue is used.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
 drivers/net/ethernet/cadence/macb.h      | 1 +
 drivers/net/ethernet/cadence/macb_main.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index c93f3a2..acb6578 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -968,6 +968,7 @@ struct macb_queue {
 	unsigned int		IMR;
 	unsigned int		TBQP;
 	unsigned int		TBQPH;
+	unsigned int		RBQP;
 
 	unsigned int		tx_head, tx_tail;
 	struct macb_dma_desc	*tx_ring;
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 72a67f7..623ae9c 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -2875,6 +2875,7 @@ static int macb_init(struct platform_device *pdev)
 			if (bp->hw_dma_cap & HW_DMA_CAP_64B)
 				queue->TBQPH = GEM_TBQPH(hw_q - 1);
 #endif
+			queue->RBQP = GEM_RBQP(hw_q - 1);
 		} else {
 			/* queue0 uses legacy registers */
 			queue->ISR  = MACB_ISR;
@@ -2886,6 +2887,7 @@ static int macb_init(struct platform_device *pdev)
 			if (bp->hw_dma_cap & HW_DMA_CAP_64B)
 				queue->TBQPH = MACB_TBQPH;
 #endif
+			queue->RBQP = MACB_RBQP;
 		}
 
 		/* get irq: here we use the linux queue index, not the hardware
-- 
2.7.4

[RFC PATCH 2/3] net: macb: Tie-off unused RX queues

[Harini Katakam]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Currently, we only use the first receive queue and leave the
remaining DMA descriptor pointers pointing at 0.

Disable unused queues by connecting them to a looped descriptor
chain without free slots.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
 drivers/net/ethernet/cadence/macb.h      |  2 ++
 drivers/net/ethernet/cadence/macb_main.c | 42 ++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index acb6578..974c801 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -994,6 +994,7 @@ struct macb {
 	unsigned int		rx_tail;
 	unsigned int		rx_prepared_head;
 	struct macb_dma_desc	*rx_ring;
+	struct macb_dma_desc	*rx_ring_tieoff;
 	struct sk_buff		**rx_skbuff;
 	void			*rx_buffers;
 	size_t			rx_buffer_size;
@@ -1019,6 +1020,7 @@ struct macb {
 	}			hw_stats;
 
 	dma_addr_t		rx_ring_dma;
+	dma_addr_t		rx_ring_tieoff_dma;
 	dma_addr_t		rx_buffers_dma;
 
 	struct macb_or_gem_ops	macbgem_ops;
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 623ae9c..b14a04d 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1755,6 +1755,12 @@ static void macb_free_consistent(struct macb *bp)
 		bp->rx_ring = NULL;
 	}
 
+	if (bp->rx_ring_tieoff) {
+		dma_free_coherent(&bp->pdev->dev, sizeof(bp->rx_ring_tieoff[0]),
+				  bp->rx_ring_tieoff, bp->rx_ring_tieoff_dma);
+		bp->rx_ring_tieoff = NULL;
+	}
+
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
 		kfree(queue->tx_skb);
 		queue->tx_skb = NULL;
@@ -1826,6 +1832,19 @@ static int macb_alloc_consistent(struct macb *bp)
 					 &bp->rx_ring_dma, GFP_KERNEL);
 	if (!bp->rx_ring)
 		goto out_err;
+
+	/* If we have more than one queue, allocate a tie off descriptor
+	 * that will be used to disable unused RX queues.
+	 */
+	if (bp->num_queues > 1) {
+		bp->rx_ring_tieoff = dma_alloc_coherent(&bp->pdev->dev,
+						sizeof(bp->rx_ring_tieoff[0]),
+						&bp->rx_ring_tieoff_dma,
+						GFP_KERNEL);
+		if (!bp->rx_ring_tieoff)
+			goto out_err;
+	}
+
 	netdev_dbg(bp->dev,
 		   "Allocated RX ring of %d bytes at %08lx (mapped %p)\n",
 		   size, (unsigned long)bp->rx_ring_dma, bp->rx_ring);
@@ -1840,6 +1859,19 @@ static int macb_alloc_consistent(struct macb *bp)
 	return -ENOMEM;
 }
 
+static void macb_init_tieoff(struct macb *bp)
+{
+	struct macb_dma_desc *d = bp->rx_ring_tieoff;
+
+	if (bp->num_queues > 1) {
+		/* Setup a wrapping descriptor with no free slots
+		 * (WRAP and USED) to tie off/disable unused RX queues.
+		 */
+		d->addr = MACB_BIT(RX_WRAP) | MACB_BIT(RX_USED);
+		d->ctrl = 0;
+	}
+}
+
 static void gem_init_rings(struct macb *bp)
 {
 	struct macb_queue *queue;
@@ -1862,6 +1894,7 @@ static void gem_init_rings(struct macb *bp)
 	bp->rx_prepared_head = 0;
 
 	gem_rx_refill(bp);
+	macb_init_tieoff(bp);
 }
 
 static void macb_init_rings(struct macb *bp)
@@ -1879,6 +1912,7 @@ static void macb_init_rings(struct macb *bp)
 	bp->queues[0].tx_head = 0;
 	bp->queues[0].tx_tail = 0;
 	desc->ctrl |= MACB_BIT(TX_WRAP);
+	macb_init_tieoff(bp);
 }
 
 static void macb_reset_hw(struct macb *bp)
@@ -2063,6 +2097,14 @@ static void macb_init_hw(struct macb *bp)
 			queue_writel(queue, TBQPH, upper_32_bits(queue->tx_ring_dma));
 #endif
 
+		/* We only use the first queue at the moment. Remaining
+		 * queues must be tied-off before we enable the receiver.
+		 *
+		 * See the documentation for receive_q1_ptr for more info.
+		 */
+		if (q)
+			queue_writel(queue, RBQP, bp->rx_ring_tieoff_dma);
+
 		/* Enable interrupts */
 		queue_writel(queue, IER,
 			     MACB_RX_INT_FLAGS |
-- 
2.7.4

[RFC PATCH 3/3] net: macb: Handle HRESP error

[Harini Katakam]

From: Harini Katakam <harini.katakam@xilinx.com>

Handle HRESP error by doing a SW reset of RX and TX and
re-initializing the descriptors, RX and TX queue pointers.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
 drivers/net/ethernet/cadence/macb.h      |  2 +
 drivers/net/ethernet/cadence/macb_main.c | 65 ++++++++++++++++++++++++++++++--
 2 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 974c801..5246ee1 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -1060,6 +1060,8 @@ struct macb {
 	struct ptp_clock_info ptp_clock_info;
 	struct tsu_incr tsu_incr;
 	struct hwtstamp_config tstamp_config;
+
+	struct tasklet_struct   hresp_err_tasklet;
 };
 
 #ifdef CONFIG_MACB_USE_HWSTAMP
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index b14a04d..d76e04f 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1244,6 +1244,63 @@ static int macb_poll(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
+static void macb_hresp_error_task(unsigned long data)
+{
+	struct macb *bp = (struct macb *)data;
+	struct net_device *dev = bp->dev;
+	struct macb_queue *queue = bp->queues;
+	unsigned int q;
+	u32 ctrl;
+
+	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
+		queue_writel(queue, IDR, MACB_RX_INT_FLAGS |
+					 MACB_TX_INT_FLAGS |
+					 MACB_BIT(HRESP));
+	}
+	ctrl = macb_readl(bp, NCR);
+	ctrl &= ~(MACB_BIT(RE) | MACB_BIT(TE));
+	macb_writel(bp, NCR, ctrl);
+
+	netif_tx_stop_all_queues(dev);
+	netif_carrier_off(dev);
+
+	bp->macbgem_ops.mog_init_rings(bp);
+
+	/* Initialize TX and RX buffers */
+	macb_writel(bp, RBQP, lower_32_bits(bp->rx_ring_dma));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+	if (bp->hw_dma_cap & HW_DMA_CAP_64B)
+		macb_writel(bp, RBQPH, upper_32_bits(bp->rx_ring_dma));
+#endif
+	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
+		queue_writel(queue, TBQP, lower_32_bits(queue->tx_ring_dma));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+		if (bp->hw_dma_cap & HW_DMA_CAP_64B)
+			queue_writel(queue, TBQPH, upper_32_bits(queue->tx_ring_dma));
+#endif
+
+		/* We only use the first queue at the moment. Remaining
+		 * queues must be tied-off before we enable the receiver.
+		 *
+		 * See the documentation for receive_q1_ptr for more info.
+		 */
+		if (q)
+			queue_writel(queue, RBQP, bp->rx_ring_tieoff_dma);
+
+		/* Enable interrupts */
+		queue_writel(queue, IER,
+			     MACB_RX_INT_FLAGS |
+			     MACB_TX_INT_FLAGS |
+			     MACB_BIT(HRESP));
+	}
+
+	ctrl |= MACB_BIT(RE) | MACB_BIT(TE);
+	macb_writel(bp, NCR, ctrl);
+
+	netif_carrier_on(dev);
+	netif_tx_start_all_queues(dev);
+}
+
 static irqreturn_t macb_interrupt(int irq, void *dev_id)
 {
 	struct macb_queue *queue = dev_id;
@@ -1333,10 +1390,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
 		}
 
 		if (status & MACB_BIT(HRESP)) {
-			/* TODO: Reset the hardware, and maybe move the
-			 * netdev_err to a lower-priority context as well
-			 * (work queue?)
-			 */
+			tasklet_schedule(&bp->hresp_err_tasklet);
 			netdev_err(dev, "DMA bus error: HRESP not OK\n");
 
 			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
@@ -3586,6 +3640,9 @@ static int macb_probe(struct platform_device *pdev)
 		goto err_out_unregister_mdio;
 	}
 
+	tasklet_init(&bp->hresp_err_tasklet, macb_hresp_error_task,
+		     (unsigned long)bp);
+
 	phy_attached_info(phydev);
 
 	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
-- 
2.7.4