[PATCH v2 0/2] Fix the arc emac driver

[PATCH v2 0/2] Fix the arc emac driver

[Andy Yan]

From: Andy Yan <andy.yan@rock-chips.com>


The arc emac driver was broken for a long time,
The first broken happens when a dma releated fix introduced in Linux 5.10.
The second broken happens when a emac device tree node restyle introduced
in Linux 6.1.

These two patches are try to make the arc emac work again.

Changes in v2:
- Add cover letter.
- Add fix tag.
- Add more detail explaination.

Johan Jonker (2):
  net: arc: fix the device for dma_map_single/dma_unmap_single
  net: arc: rockchip: fix emac mdio node support

 drivers/net/ethernet/arc/emac_main.c | 27 ++++++++++++++++-----------
 drivers/net/ethernet/arc/emac_mdio.c |  9 ++++++++-
 2 files changed, 24 insertions(+), 12 deletions(-)

-- 
2.34.1

[PATCH v2 1/2] net: arc: fix the device for dma_map_single/dma_unmap_single

[Andy Yan]

From: Johan Jonker <jbx6244@gmail.com>

The ndev->dev and pdev->dev aren't the same device, use ndev->dev.parent
which has dma_mask, ndev->dev.parent is just pdev->dev.
Or it would cause the following issue:

[   39.933526] ------------[ cut here ]------------
[   39.938414] WARNING: CPU: 1 PID: 501 at kernel/dma/mapping.c:149 dma_map_page_attrs+0x90/0x1f8

Fixes: f959dcd6ddfd ("dma-direct: Fix potential NULL pointer dereference")
Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v2:
- Add fix tag.
- Add cover letter.

 drivers/net/ethernet/arc/emac_main.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
index 31ee477dd131e..8283aeee35fb6 100644
--- a/drivers/net/ethernet/arc/emac_main.c
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -111,6 +111,7 @@ static void arc_emac_tx_clean(struct net_device *ndev)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
 	struct net_device_stats *stats = &ndev->stats;
+	struct device *dev = ndev->dev.parent;
 	unsigned int i;
 
 	for (i = 0; i < TX_BD_NUM; i++) {
@@ -140,7 +141,7 @@ static void arc_emac_tx_clean(struct net_device *ndev)
 			stats->tx_bytes += skb->len;
 		}
 
-		dma_unmap_single(&ndev->dev, dma_unmap_addr(tx_buff, addr),
+		dma_unmap_single(dev, dma_unmap_addr(tx_buff, addr),
 				 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);
 
 		/* return the sk_buff to system */
@@ -174,6 +175,7 @@ static void arc_emac_tx_clean(struct net_device *ndev)
 static int arc_emac_rx(struct net_device *ndev, int budget)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
 	unsigned int work_done;
 
 	for (work_done = 0; work_done < budget; work_done++) {
@@ -223,9 +225,9 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
 			continue;
 		}
 
-		addr = dma_map_single(&ndev->dev, (void *)skb->data,
+		addr = dma_map_single(dev, (void *)skb->data,
 				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
-		if (dma_mapping_error(&ndev->dev, addr)) {
+		if (dma_mapping_error(dev, addr)) {
 			if (net_ratelimit())
 				netdev_err(ndev, "cannot map dma buffer\n");
 			dev_kfree_skb(skb);
@@ -237,7 +239,7 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
 		}
 
 		/* unmap previosly mapped skb */
-		dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
+		dma_unmap_single(dev, dma_unmap_addr(rx_buff, addr),
 				 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
 
 		pktlen = info & LEN_MASK;
@@ -423,6 +425,7 @@ static int arc_emac_open(struct net_device *ndev)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
 	struct phy_device *phy_dev = ndev->phydev;
+	struct device *dev = ndev->dev.parent;
 	int i;
 
 	phy_dev->autoneg = AUTONEG_ENABLE;
@@ -445,9 +448,9 @@ static int arc_emac_open(struct net_device *ndev)
 		if (unlikely(!rx_buff->skb))
 			return -ENOMEM;
 
-		addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
+		addr = dma_map_single(dev, (void *)rx_buff->skb->data,
 				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
-		if (dma_mapping_error(&ndev->dev, addr)) {
+		if (dma_mapping_error(dev, addr)) {
 			netdev_err(ndev, "cannot dma map\n");
 			dev_kfree_skb(rx_buff->skb);
 			return -ENOMEM;
@@ -548,6 +551,7 @@ static void arc_emac_set_rx_mode(struct net_device *ndev)
 static void arc_free_tx_queue(struct net_device *ndev)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
 	unsigned int i;
 
 	for (i = 0; i < TX_BD_NUM; i++) {
@@ -555,7 +559,7 @@ static void arc_free_tx_queue(struct net_device *ndev)
 		struct buffer_state *tx_buff = &priv->tx_buff[i];
 
 		if (tx_buff->skb) {
-			dma_unmap_single(&ndev->dev,
+			dma_unmap_single(dev,
 					 dma_unmap_addr(tx_buff, addr),
 					 dma_unmap_len(tx_buff, len),
 					 DMA_TO_DEVICE);
@@ -579,6 +583,7 @@ static void arc_free_tx_queue(struct net_device *ndev)
 static void arc_free_rx_queue(struct net_device *ndev)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
 	unsigned int i;
 
 	for (i = 0; i < RX_BD_NUM; i++) {
@@ -586,7 +591,7 @@ static void arc_free_rx_queue(struct net_device *ndev)
 		struct buffer_state *rx_buff = &priv->rx_buff[i];
 
 		if (rx_buff->skb) {
-			dma_unmap_single(&ndev->dev,
+			dma_unmap_single(dev,
 					 dma_unmap_addr(rx_buff, addr),
 					 dma_unmap_len(rx_buff, len),
 					 DMA_FROM_DEVICE);
@@ -679,6 +684,7 @@ static netdev_tx_t arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
 	unsigned int len, *txbd_curr = &priv->txbd_curr;
 	struct net_device_stats *stats = &ndev->stats;
 	__le32 *info = &priv->txbd[*txbd_curr].info;
+	struct device *dev = ndev->dev.parent;
 	dma_addr_t addr;
 
 	if (skb_padto(skb, ETH_ZLEN))
@@ -692,10 +698,9 @@ static netdev_tx_t arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
 		return NETDEV_TX_BUSY;
 	}
 
-	addr = dma_map_single(&ndev->dev, (void *)skb->data, len,
-			      DMA_TO_DEVICE);
+	addr = dma_map_single(dev, (void *)skb->data, len, DMA_TO_DEVICE);
 
-	if (unlikely(dma_mapping_error(&ndev->dev, addr))) {
+	if (unlikely(dma_mapping_error(dev, addr))) {
 		stats->tx_dropped++;
 		stats->tx_errors++;
 		dev_kfree_skb_any(skb);
-- 
2.34.1

[PATCH v2 2/2] net: arc: rockchip: fix emac mdio node support

[Andy Yan]

From: Johan Jonker <jbx6244@gmail.com>

The binding emac_rockchip.txt is converted to YAML.
Changed against the original binding is an added MDIO subnode.
This make the driver failed to find the PHY, and given the 'mdio
has invalid PHY address' it is probably looking in the wrong node.
Fix emac_mdio.c so that it can handle both old and new
device trees.

Fixes: 1dabb74971b3 ("ARM: dts: rockchip: restyle emac nodes")
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Tested-by: Andy Yan <andyshrk@163.com>
Link: https://lore.kernel.org/r/20220603163539.537-3-jbx6244@gmail.com
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v2:
- Add fix tag.
- Add more detail explaination.

 drivers/net/ethernet/arc/emac_mdio.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c
index 87f40c2ba9040..078b1a72c1613 100644
--- a/drivers/net/ethernet/arc/emac_mdio.c
+++ b/drivers/net/ethernet/arc/emac_mdio.c
@@ -133,6 +133,7 @@ int arc_mdio_probe(struct arc_emac_priv *priv)
 	struct arc_emac_mdio_bus_data *data = &priv->bus_data;
 	struct device_node *np = priv->dev->of_node;
 	const char *name = "Synopsys MII Bus";
+	struct device_node *mdio_node;
 	struct mii_bus *bus;
 	int error;
 
@@ -164,7 +165,13 @@ int arc_mdio_probe(struct arc_emac_priv *priv)
 
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
 
-	error = of_mdiobus_register(bus, priv->dev->of_node);
+	/* Backwards compatibility for EMAC nodes without MDIO subnode. */
+	mdio_node = of_get_child_by_name(np, "mdio");
+	if (!mdio_node)
+		mdio_node = of_node_get(np);
+
+	error = of_mdiobus_register(bus, mdio_node);
+	of_node_put(mdio_node);
 	if (error) {
 		mdiobus_free(bus);
 		return dev_err_probe(priv->dev, error,
-- 
2.34.1

Re: [PATCH v2 2/2] net: arc: rockchip: fix emac mdio node support

[Jakub Kicinski]

On Mon,  4 Nov 2024 21:01:39 +0800 Andy Yan wrote:
> From: Johan Jonker <jbx6244@gmail.com>
> 
> The binding emac_rockchip.txt is converted to YAML.
> Changed against the original binding is an added MDIO subnode.
> This make the driver failed to find the PHY, and given the 'mdio
> has invalid PHY address' it is probably looking in the wrong node.
> Fix emac_mdio.c so that it can handle both old and new
> device trees.

Andrew, looks good?

Re: [PATCH v2 2/2] net: arc: rockchip: fix emac mdio node support

[Andrew Lunn]

On Wed, Nov 06, 2024 at 05:50:02PM -0800, Jakub Kicinski wrote:
> On Mon,  4 Nov 2024 21:01:39 +0800 Andy Yan wrote:
> > From: Johan Jonker <jbx6244@gmail.com>
> > 
> > The binding emac_rockchip.txt is converted to YAML.
> > Changed against the original binding is an added MDIO subnode.
> > This make the driver failed to find the PHY, and given the 'mdio
> > has invalid PHY address' it is probably looking in the wrong node.
> > Fix emac_mdio.c so that it can handle both old and new
> > device trees.
> 
> Andrew, looks good?

The MDIO patch looks correct. I cannot say anything about the DMA
mapping.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH v2 0/2] Fix the arc emac driver

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Mon,  4 Nov 2024 21:01:37 +0800 you wrote:
> From: Andy Yan <andy.yan@rock-chips.com>
> 
> 
> The arc emac driver was broken for a long time,
> The first broken happens when a dma releated fix introduced in Linux 5.10.
> The second broken happens when a emac device tree node restyle introduced
> in Linux 6.1.
> 
> [...]

Here is the summary with links:
  - [v2,1/2] net: arc: fix the device for dma_map_single/dma_unmap_single
    https://git.kernel.org/netdev/net/c/71803c1dfa29
  - [v2,2/2] net: arc: rockchip: fix emac mdio node support
    https://git.kernel.org/netdev/net/c/0a1c7a7b0adb

You are awesome, thank you!
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