[PATCH net-next 0/4] net: ll_temac: RX/TX ring size and coalesce ethtool parameters

[PATCH net-next 0/4] net: ll_temac: RX/TX ring size and coalesce ethtool parameters

[Esben Haabendal]

This series adds support for RX/TX ring size and irq coalesce ethtool
parameters to ll_temac driver.

Esben Haabendal (4):
  net: ll_temac: Remove unused tx_bd_next struct field
  net: ll_temac: Remove unused start_p variable
  net: ll_temac: Make RX/TX ring sizes configurable
  net: ll_temac: Add ethtool support for coalesce parameters

 drivers/net/ethernet/xilinx/ll_temac.h      |   8 +-
 drivers/net/ethernet/xilinx/ll_temac_main.c | 198 +++++++++++++++-----
 2 files changed, 154 insertions(+), 52 deletions(-)

-- 
2.25.1

[PATCH net-next 1/4] net: ll_temac: Remove unused tx_bd_next struct field

[Esben Haabendal]

The tx_bd_next field was included in the initial commit,
commit 92744989533c ("net: add Xilinx ll_temac device driver"),
but has never had any real use.

Signed-off-by: Esben Haabendal <esben@geanix.com>
---
 drivers/net/ethernet/xilinx/ll_temac.h      | 1 -
 drivers/net/ethernet/xilinx/ll_temac_main.c | 1 -
 2 files changed, 2 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/ll_temac.h b/drivers/net/ethernet/xilinx/ll_temac.h
index 53fb8141f1a6..463ef9eaf42d 100644
--- a/drivers/net/ethernet/xilinx/ll_temac.h
+++ b/drivers/net/ethernet/xilinx/ll_temac.h
@@ -372,7 +372,6 @@ struct temac_local {
 	struct cdmac_bd *rx_bd_v;
 	dma_addr_t rx_bd_p;
 	int tx_bd_ci;
-	int tx_bd_next;
 	int tx_bd_tail;
 	int rx_bd_ci;
 	int rx_bd_tail;
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 9461acec6f70..b0fab9a2056f 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -387,7 +387,6 @@ static int temac_dma_bd_init(struct net_device *ndev)
 
 	/* Init descriptor indexes */
 	lp->tx_bd_ci = 0;
-	lp->tx_bd_next = 0;
 	lp->tx_bd_tail = 0;
 	lp->rx_bd_ci = 0;
 	lp->rx_bd_tail = RX_BD_NUM - 1;
-- 
2.25.1

[PATCH net-next 2/4] net: ll_temac: Remove unused start_p variable

[Esben Haabendal]

The start_p variable was included in the initial commit,
commit 92744989533c ("net: add Xilinx ll_temac device driver"),
but has never had any real use.

Signed-off-by: Esben Haabendal <esben@geanix.com>
---
 drivers/net/ethernet/xilinx/ll_temac_main.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index b0fab9a2056f..d6853c44e672 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -825,14 +825,13 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	struct temac_local *lp = netdev_priv(ndev);
 	struct cdmac_bd *cur_p;
-	dma_addr_t start_p, tail_p, skb_dma_addr;
+	dma_addr_t tail_p, skb_dma_addr;
 	int ii;
 	unsigned long num_frag;
 	skb_frag_t *frag;
 
 	num_frag = skb_shinfo(skb)->nr_frags;
 	frag = &skb_shinfo(skb)->frags[0];
-	start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail;
 	cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
 
 	if (temac_check_tx_bd_space(lp, num_frag + 1)) {
-- 
2.25.1

[PATCH net-next 3/4] net: ll_temac: Make RX/TX ring sizes configurable

[Esben Haabendal]

Add support for setting the RX and TX ring sizes for this driver using
ethtool. Also increase the default RX ring size as the previous default
was far too low for good performance in some configurations.

Signed-off-by: Esben Haabendal <esben@geanix.com>
---
 drivers/net/ethernet/xilinx/ll_temac.h      |  2 +
 drivers/net/ethernet/xilinx/ll_temac_main.c | 96 +++++++++++++++------
 2 files changed, 72 insertions(+), 26 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/ll_temac.h b/drivers/net/ethernet/xilinx/ll_temac.h
index 463ef9eaf42d..8777ec6e21c8 100644
--- a/drivers/net/ethernet/xilinx/ll_temac.h
+++ b/drivers/net/ethernet/xilinx/ll_temac.h
@@ -369,8 +369,10 @@ struct temac_local {
 	/* Buffer descriptors */
 	struct cdmac_bd *tx_bd_v;
 	dma_addr_t tx_bd_p;
+	u32 tx_bd_num;
 	struct cdmac_bd *rx_bd_v;
 	dma_addr_t rx_bd_p;
+	u32 rx_bd_num;
 	int tx_bd_ci;
 	int tx_bd_tail;
 	int rx_bd_ci;
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index d6853c44e672..5735acb44b57 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -58,8 +58,11 @@
 
 #include "ll_temac.h"
 
-#define TX_BD_NUM   64
-#define RX_BD_NUM   128
+/* Descriptors defines for Tx and Rx DMA */
+#define TX_BD_NUM_DEFAULT		64
+#define RX_BD_NUM_DEFAULT		1024
+#define TX_BD_NUM_MAX			4096
+#define RX_BD_NUM_MAX			4096
 
 /* ---------------------------------------------------------------------
  * Low level register access functions
@@ -301,7 +304,7 @@ static void temac_dma_bd_release(struct net_device *ndev)
 	/* Reset Local Link (DMA) */
 	lp->dma_out(lp, DMA_CONTROL_REG, DMA_CONTROL_RST);
 
-	for (i = 0; i < RX_BD_NUM; i++) {
+	for (i = 0; i < lp->rx_bd_num; i++) {
 		if (!lp->rx_skb[i])
 			break;
 		else {
@@ -312,12 +315,12 @@ static void temac_dma_bd_release(struct net_device *ndev)
 	}
 	if (lp->rx_bd_v)
 		dma_free_coherent(ndev->dev.parent,
-				sizeof(*lp->rx_bd_v) * RX_BD_NUM,
-				lp->rx_bd_v, lp->rx_bd_p);
+				  sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
+				  lp->rx_bd_v, lp->rx_bd_p);
 	if (lp->tx_bd_v)
 		dma_free_coherent(ndev->dev.parent,
-				sizeof(*lp->tx_bd_v) * TX_BD_NUM,
-				lp->tx_bd_v, lp->tx_bd_p);
+				  sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
+				  lp->tx_bd_v, lp->tx_bd_p);
 }
 
 /**
@@ -330,33 +333,33 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	dma_addr_t skb_dma_addr;
 	int i;
 
-	lp->rx_skb = devm_kcalloc(&ndev->dev, RX_BD_NUM, sizeof(*lp->rx_skb),
-				  GFP_KERNEL);
+	lp->rx_skb = devm_kcalloc(&ndev->dev, lp->rx_bd_num,
+				  sizeof(*lp->rx_skb), GFP_KERNEL);
 	if (!lp->rx_skb)
 		goto out;
 
 	/* allocate the tx and rx ring buffer descriptors. */
 	/* returns a virtual address and a physical address. */
 	lp->tx_bd_v = dma_alloc_coherent(ndev->dev.parent,
-					 sizeof(*lp->tx_bd_v) * TX_BD_NUM,
+					 sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
 					 &lp->tx_bd_p, GFP_KERNEL);
 	if (!lp->tx_bd_v)
 		goto out;
 
 	lp->rx_bd_v = dma_alloc_coherent(ndev->dev.parent,
-					 sizeof(*lp->rx_bd_v) * RX_BD_NUM,
+					 sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
 					 &lp->rx_bd_p, GFP_KERNEL);
 	if (!lp->rx_bd_v)
 		goto out;
 
-	for (i = 0; i < TX_BD_NUM; i++) {
+	for (i = 0; i < lp->tx_bd_num; i++) {
 		lp->tx_bd_v[i].next = cpu_to_be32(lp->tx_bd_p
-				+ sizeof(*lp->tx_bd_v) * ((i + 1) % TX_BD_NUM));
+			+ sizeof(*lp->tx_bd_v) * ((i + 1) % lp->tx_bd_num));
 	}
 
-	for (i = 0; i < RX_BD_NUM; i++) {
+	for (i = 0; i < lp->rx_bd_num; i++) {
 		lp->rx_bd_v[i].next = cpu_to_be32(lp->rx_bd_p
-				+ sizeof(*lp->rx_bd_v) * ((i + 1) % RX_BD_NUM));
+			+ sizeof(*lp->rx_bd_v) * ((i + 1) % lp->rx_bd_num));
 
 		skb = netdev_alloc_skb_ip_align(ndev,
 						XTE_MAX_JUMBO_FRAME_SIZE);
@@ -389,7 +392,7 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	lp->tx_bd_ci = 0;
 	lp->tx_bd_tail = 0;
 	lp->rx_bd_ci = 0;
-	lp->rx_bd_tail = RX_BD_NUM - 1;
+	lp->rx_bd_tail = lp->rx_bd_num - 1;
 
 	/* Enable RX DMA transfers */
 	wmb();
@@ -784,7 +787,7 @@ static void temac_start_xmit_done(struct net_device *ndev)
 		ndev->stats.tx_bytes += be32_to_cpu(cur_p->len);
 
 		lp->tx_bd_ci++;
-		if (lp->tx_bd_ci >= TX_BD_NUM)
+		if (lp->tx_bd_ci >= lp->tx_bd_num)
 			lp->tx_bd_ci = 0;
 
 		cur_p = &lp->tx_bd_v[lp->tx_bd_ci];
@@ -810,7 +813,7 @@ static inline int temac_check_tx_bd_space(struct temac_local *lp, int num_frag)
 			return NETDEV_TX_BUSY;
 
 		tail++;
-		if (tail >= TX_BD_NUM)
+		if (tail >= lp->tx_bd_num)
 			tail = 0;
 
 		cur_p = &lp->tx_bd_v[tail];
@@ -874,7 +877,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	ptr_to_txbd((void *)skb, cur_p);
 
 	for (ii = 0; ii < num_frag; ii++) {
-		if (++lp->tx_bd_tail >= TX_BD_NUM)
+		if (++lp->tx_bd_tail >= lp->tx_bd_num)
 			lp->tx_bd_tail = 0;
 
 		cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
@@ -884,7 +887,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 					      DMA_TO_DEVICE);
 		if (dma_mapping_error(ndev->dev.parent, skb_dma_addr)) {
 			if (--lp->tx_bd_tail < 0)
-				lp->tx_bd_tail = TX_BD_NUM - 1;
+				lp->tx_bd_tail = lp->tx_bd_num - 1;
 			cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
 			while (--ii >= 0) {
 				--frag;
@@ -893,7 +896,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 						 skb_frag_size(frag),
 						 DMA_TO_DEVICE);
 				if (--lp->tx_bd_tail < 0)
-					lp->tx_bd_tail = TX_BD_NUM - 1;
+					lp->tx_bd_tail = lp->tx_bd_num - 1;
 				cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
 			}
 			dma_unmap_single(ndev->dev.parent,
@@ -912,7 +915,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 
 	tail_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail;
 	lp->tx_bd_tail++;
-	if (lp->tx_bd_tail >= TX_BD_NUM)
+	if (lp->tx_bd_tail >= lp->tx_bd_num)
 		lp->tx_bd_tail = 0;
 
 	skb_tx_timestamp(skb);
@@ -932,7 +935,7 @@ static int ll_temac_recv_buffers_available(struct temac_local *lp)
 		return 0;
 	available = 1 + lp->rx_bd_tail - lp->rx_bd_ci;
 	if (available <= 0)
-		available += RX_BD_NUM;
+		available += lp->rx_bd_num;
 	return available;
 }
 
@@ -1001,7 +1004,7 @@ static void ll_temac_recv(struct net_device *ndev)
 		ndev->stats.rx_bytes += length;
 
 		rx_bd = lp->rx_bd_ci;
-		if (++lp->rx_bd_ci >= RX_BD_NUM)
+		if (++lp->rx_bd_ci >= lp->rx_bd_num)
 			lp->rx_bd_ci = 0;
 	} while (rx_bd != lp->rx_bd_tail);
 
@@ -1032,7 +1035,7 @@ static void ll_temac_recv(struct net_device *ndev)
 		dma_addr_t skb_dma_addr;
 
 		rx_bd = lp->rx_bd_tail + 1;
-		if (rx_bd >= RX_BD_NUM)
+		if (rx_bd >= lp->rx_bd_num)
 			rx_bd = 0;
 		bd = &lp->rx_bd_v[rx_bd];
 
@@ -1248,13 +1251,52 @@ static const struct attribute_group temac_attr_group = {
 	.attrs = temac_device_attrs,
 };
 
-/* ethtool support */
+/* ---------------------------------------------------------------------
+ * ethtool support
+ */
+
+static void ll_temac_ethtools_get_ringparam(struct net_device *ndev,
+					    struct ethtool_ringparam *ering)
+{
+	struct temac_local *lp = netdev_priv(ndev);
+
+	ering->rx_max_pending = RX_BD_NUM_MAX;
+	ering->rx_mini_max_pending = 0;
+	ering->rx_jumbo_max_pending = 0;
+	ering->tx_max_pending = TX_BD_NUM_MAX;
+	ering->rx_pending = lp->rx_bd_num;
+	ering->rx_mini_pending = 0;
+	ering->rx_jumbo_pending = 0;
+	ering->tx_pending = lp->tx_bd_num;
+}
+
+static int ll_temac_ethtools_set_ringparam(struct net_device *ndev,
+					   struct ethtool_ringparam *ering)
+{
+	struct temac_local *lp = netdev_priv(ndev);
+
+	if (ering->rx_pending > RX_BD_NUM_MAX ||
+	    ering->rx_mini_pending ||
+	    ering->rx_jumbo_pending ||
+	    ering->rx_pending > TX_BD_NUM_MAX)
+		return -EINVAL;
+
+	if (netif_running(ndev))
+		return -EBUSY;
+
+	lp->rx_bd_num = ering->rx_pending;
+	lp->tx_bd_num = ering->tx_pending;
+	return 0;
+}
+
 static const struct ethtool_ops temac_ethtool_ops = {
 	.nway_reset = phy_ethtool_nway_reset,
 	.get_link = ethtool_op_get_link,
 	.get_ts_info = ethtool_op_get_ts_info,
 	.get_link_ksettings = phy_ethtool_get_link_ksettings,
 	.set_link_ksettings = phy_ethtool_set_link_ksettings,
+	.get_ringparam	= ll_temac_ethtools_get_ringparam,
+	.set_ringparam	= ll_temac_ethtools_set_ringparam,
 };
 
 static int temac_probe(struct platform_device *pdev)
@@ -1298,6 +1340,8 @@ static int temac_probe(struct platform_device *pdev)
 	lp->ndev = ndev;
 	lp->dev = &pdev->dev;
 	lp->options = XTE_OPTION_DEFAULTS;
+	lp->rx_bd_num = RX_BD_NUM_DEFAULT;
+	lp->tx_bd_num = TX_BD_NUM_DEFAULT;
 	spin_lock_init(&lp->rx_lock);
 	INIT_DELAYED_WORK(&lp->restart_work, ll_temac_restart_work_func);
 
-- 
2.25.1

[PATCH net-next 4/4] net: ll_temac: Add ethtool support for coalesce parameters

[Esben Haabendal]

Please note that the delays are calculated based on typical
parameters.  But as TEMAC is an HDL IP, designs may vary, and future
work might be needed to make this calculation configurable.

Signed-off-by: Esben Haabendal <esben@geanix.com>
---
 drivers/net/ethernet/xilinx/ll_temac.h      |  5 +-
 drivers/net/ethernet/xilinx/ll_temac_main.c | 98 ++++++++++++++++-----
 2 files changed, 81 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/ll_temac.h b/drivers/net/ethernet/xilinx/ll_temac.h
index 8777ec6e21c8..4a73127e10a6 100644
--- a/drivers/net/ethernet/xilinx/ll_temac.h
+++ b/drivers/net/ethernet/xilinx/ll_temac.h
@@ -379,9 +379,10 @@ struct temac_local {
 	int rx_bd_tail;
 
 	/* DMA channel control setup */
-	u32 tx_chnl_ctrl;
-	u32 rx_chnl_ctrl;
+	u8 coalesce_count_tx;
+	u8 coalesce_delay_tx;
 	u8 coalesce_count_rx;
+	u8 coalesce_delay_rx;
 
 	struct delayed_work restart_work;
 };
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 5735acb44b57..dc022cd5bc42 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -379,11 +379,13 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	}
 
 	/* Configure DMA channel (irq setup) */
-	lp->dma_out(lp, TX_CHNL_CTRL, lp->tx_chnl_ctrl |
+	lp->dma_out(lp, TX_CHNL_CTRL,
+		    lp->coalesce_delay_tx << 24 | lp->coalesce_count_tx << 16 |
 		    0x00000400 | // Use 1 Bit Wide Counters. Currently Not Used!
 		    CHNL_CTRL_IRQ_EN | CHNL_CTRL_IRQ_ERR_EN |
 		    CHNL_CTRL_IRQ_DLY_EN | CHNL_CTRL_IRQ_COAL_EN);
-	lp->dma_out(lp, RX_CHNL_CTRL, lp->rx_chnl_ctrl |
+	lp->dma_out(lp, RX_CHNL_CTRL,
+		    lp->coalesce_delay_rx << 24 | lp->coalesce_count_rx << 16 |
 		    CHNL_CTRL_IRQ_IOE |
 		    CHNL_CTRL_IRQ_EN | CHNL_CTRL_IRQ_ERR_EN |
 		    CHNL_CTRL_IRQ_DLY_EN | CHNL_CTRL_IRQ_COAL_EN);
@@ -1289,6 +1291,65 @@ static int ll_temac_ethtools_set_ringparam(struct net_device *ndev,
 	return 0;
 }
 
+static int ll_temac_ethtools_get_coalesce(struct net_device *ndev,
+					  struct ethtool_coalesce *ec)
+{
+	struct temac_local *lp = netdev_priv(ndev);
+
+	ec->rx_max_coalesced_frames = lp->coalesce_count_rx;
+	ec->tx_max_coalesced_frames = lp->coalesce_count_tx;
+	ec->rx_coalesce_usecs = (lp->coalesce_delay_rx * 512) / 100;
+	ec->tx_coalesce_usecs = (lp->coalesce_delay_tx * 512) / 100;
+	return 0;
+}
+
+static int ll_temac_ethtools_set_coalesce(struct net_device *ndev,
+					  struct ethtool_coalesce *ec)
+{
+	struct temac_local *lp = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		netdev_err(ndev,
+			   "Please stop netif before applying configuration\n");
+		return -EFAULT;
+	}
+
+	if (ec->rx_coalesce_usecs_irq ||
+	    ec->rx_max_coalesced_frames_irq ||
+	    ec->tx_coalesce_usecs_irq ||
+	    ec->tx_max_coalesced_frames_irq ||
+	    ec->stats_block_coalesce_usecs ||
+	    ec->use_adaptive_rx_coalesce ||
+	    ec->use_adaptive_tx_coalesce ||
+	    ec->pkt_rate_low ||
+	    ec->rx_coalesce_usecs_low ||
+	    ec->rx_max_coalesced_frames_low ||
+	    ec->tx_coalesce_usecs_low ||
+	    ec->tx_max_coalesced_frames_low ||
+	    ec->pkt_rate_high ||
+	    ec->rx_coalesce_usecs_high ||
+	    ec->rx_max_coalesced_frames_high ||
+	    ec->tx_coalesce_usecs_high ||
+	    ec->tx_max_coalesced_frames_high ||
+	    ec->rate_sample_interval)
+		return -EOPNOTSUPP;
+	if (ec->rx_max_coalesced_frames)
+		lp->coalesce_count_rx = ec->rx_max_coalesced_frames;
+	if (ec->tx_max_coalesced_frames)
+		lp->coalesce_count_tx = ec->tx_max_coalesced_frames;
+	/* With typical LocalLink clock speed of 200 MHz and
+	 * C_PRESCALAR=1023, each delay count corresponds to 5.12 us.
+	 */
+	if (ec->rx_coalesce_usecs)
+		lp->coalesce_delay_rx =
+			min(255U, (ec->rx_coalesce_usecs * 100) / 512);
+	if (ec->tx_coalesce_usecs)
+		lp->coalesce_delay_tx =
+			min(255U, (ec->tx_coalesce_usecs * 100) / 512);
+
+	return 0;
+}
+
 static const struct ethtool_ops temac_ethtool_ops = {
 	.nway_reset = phy_ethtool_nway_reset,
 	.get_link = ethtool_op_get_link,
@@ -1297,6 +1358,8 @@ static const struct ethtool_ops temac_ethtool_ops = {
 	.set_link_ksettings = phy_ethtool_set_link_ksettings,
 	.get_ringparam	= ll_temac_ethtools_get_ringparam,
 	.set_ringparam	= ll_temac_ethtools_set_ringparam,
+	.get_coalesce	= ll_temac_ethtools_get_coalesce,
+	.set_coalesce	= ll_temac_ethtools_set_coalesce,
 };
 
 static int temac_probe(struct platform_device *pdev)
@@ -1406,6 +1469,14 @@ static int temac_probe(struct platform_device *pdev)
 		/* Can checksum TCP/UDP over IPv4. */
 		ndev->features |= NETIF_F_IP_CSUM;
 
+	/* Defaults for IRQ delay/coalescing setup.  These are
+	 * configuration values, so does not belong in device-tree.
+	 */
+	lp->coalesce_delay_tx = 0x10;
+	lp->coalesce_count_tx = 0x22;
+	lp->coalesce_delay_rx = 0xff;
+	lp->coalesce_count_rx = 0x07;
+
 	/* Setup LocalLink DMA */
 	if (temac_np) {
 		/* Find the DMA node, map the DMA registers, and
@@ -1444,14 +1515,6 @@ static int temac_probe(struct platform_device *pdev)
 		lp->rx_irq = irq_of_parse_and_map(dma_np, 0);
 		lp->tx_irq = irq_of_parse_and_map(dma_np, 1);
 
-		/* Use defaults for IRQ delay/coalescing setup.  These
-		 * are configuration values, so does not belong in
-		 * device-tree.
-		 */
-		lp->tx_chnl_ctrl = 0x10220000;
-		lp->rx_chnl_ctrl = 0xff070000;
-		lp->coalesce_count_rx = 0x07;
-
 		/* Finished with the DMA node; drop the reference */
 		of_node_put(dma_np);
 	} else if (pdata) {
@@ -1477,18 +1540,13 @@ static int temac_probe(struct platform_device *pdev)
 		lp->tx_irq = platform_get_irq(pdev, 1);
 
 		/* IRQ delay/coalescing setup */
-		if (pdata->tx_irq_timeout || pdata->tx_irq_count)
-			lp->tx_chnl_ctrl = (pdata->tx_irq_timeout << 24) |
-				(pdata->tx_irq_count << 16);
-		else
-			lp->tx_chnl_ctrl = 0x10220000;
+		if (pdata->tx_irq_timeout || pdata->tx_irq_count) {
+			lp->coalesce_delay_tx = pdata->tx_irq_timeout;
+			lp->coalesce_count_tx = pdata->tx_irq_count;
+		}
 		if (pdata->rx_irq_timeout || pdata->rx_irq_count) {
-			lp->rx_chnl_ctrl = (pdata->rx_irq_timeout << 24) |
-				(pdata->rx_irq_count << 16);
+			lp->coalesce_delay_rx = pdata->rx_irq_timeout;
 			lp->coalesce_count_rx = pdata->rx_irq_count;
-		} else {
-			lp->rx_chnl_ctrl = 0xff070000;
-			lp->coalesce_count_rx = 0x07;
 		}
 	}
 
-- 
2.25.1

Re: [PATCH net-next 0/4] net: ll_temac: RX/TX ring size and coalesce ethtool parameters

[David Miller]

From: Esben Haabendal <esben@geanix.com>
Date: Fri, 28 Feb 2020 08:56:42 +0100

> This series adds support for RX/TX ring size and irq coalesce ethtool
> parameters to ll_temac driver.
> 
> Esben Haabendal (4):
>   net: ll_temac: Remove unused tx_bd_next struct field
>   net: ll_temac: Remove unused start_p variable
>   net: ll_temac: Make RX/TX ring sizes configurable
>   net: ll_temac: Add ethtool support for coalesce parameters

Series applied, thanks.

I supposed not allowing the ring param change when the device is up is
one way to avoid the complexity of handling failures.

However, users may find this very limiting since most networking
devices allow this operation when the device is up and running.