[PATCH net-next 0/3] net: hns: add deferred probe and fix a bug

[PATCH net-next 0/3] net: hns: add deferred probe and fix a bug

[Yankejian]

This series adds support defered probe to avoid no mdio scene, and will
fix a bug that skb may be freed several times.

lipeng (3):
  net: hns: support deferred probe when can not obtain irq
  net: hns: support deferred probe when no mdio
  net: hns: fixed bug that skb used after kfree

 drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c  | 34 ++++++++++++++++++----
 drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c | 12 ++++++++
 drivers/net/ethernet/hisilicon/hns/hns_enet.c      | 22 +++++++-------
 drivers/net/ethernet/hisilicon/hns/hns_enet.h      |  6 ++--
 4 files changed, 53 insertions(+), 21 deletions(-)

-- 
1.9.1

[PATCH net-next 1/3] net: hns: support deferred probe when can not obtain irq

[Yankejian]

From: lipeng <lipeng321@huawei.com>

In the hip06 and hip07 SoCs, the interrupt lines from the
DSAF controllers are connected to mbigen hw module.
The mbigen module is probed with module_init, and, as such,
is not guaranteed to probe before the HNS driver. So we need
to support deferred probe.

We check for probe deferral in the hw layer probe, so we not
probe into the main layer and memories, etc., to later learn
that we need to defer the probe.

Signed-off-by: lipeng <lipeng321@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
index 403ea9d..2da5b42 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
@@ -2971,6 +2971,18 @@ static int hns_dsaf_probe(struct platform_device *pdev)
 	struct dsaf_device *dsaf_dev;
 	int ret;
 
+	/*
+	 * Check if we should defer the probe before we probe the
+	 * dsaf, as it's hard to defer later on.
+	 */
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Cannot obtain irq\n");
+
+		return ret;
+	}
+
 	dsaf_dev = hns_dsaf_alloc_dev(&pdev->dev, sizeof(struct dsaf_drv_priv));
 	if (IS_ERR(dsaf_dev)) {
 		ret = PTR_ERR(dsaf_dev);
-- 
1.9.1

[PATCH net-next 2/3] net: hns: support deferred probe when no mdio

[Yankejian]

From: lipeng <lipeng321@huawei.com>

In the hip06 and hip07 SoCs, phy connect to mdio bus.The mdio
module is probed with module_init, and, as such,
is not guaranteed to probe before the HNS driver. So we need
to support deferred probe.

We check for probe deferral in the mac init, so we not init DSAF
when there is no mdio, and free all resource, to later learn that
we need to defer the probe.

Signed-off-by: lipeng <lipeng321@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c | 34 +++++++++++++++++++----
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
index bdd8cdd..284ebfe 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
@@ -735,6 +735,8 @@ static int hns_mac_init_ex(struct hns_mac_cb *mac_cb)
 	rc = phy_device_register(phy);
 	if (rc) {
 		phy_device_free(phy);
+		dev_err(&mdio->dev, "registered phy fail at address %i\n",
+			addr);
 		return -ENODEV;
 	}
 
@@ -745,7 +747,7 @@ static int hns_mac_init_ex(struct hns_mac_cb *mac_cb)
 	return 0;
 }
 
-static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
+static int hns_mac_register_phy(struct hns_mac_cb *mac_cb)
 {
 	struct acpi_reference_args args;
 	struct platform_device *pdev;
@@ -755,24 +757,39 @@ static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
 
 	/* Loop over the child nodes and register a phy_device for each one */
 	if (!to_acpi_device_node(mac_cb->fw_port))
-		return;
+		return 0;
 
 	rc = acpi_node_get_property_reference(
 			mac_cb->fw_port, "mdio-node", 0, &args);
 	if (rc)
-		return;
+		return 0;
 
 	addr = hns_mac_phy_parse_addr(mac_cb->dev, mac_cb->fw_port);
 	if (addr < 0)
-		return;
+		return 0;
 
 	/* dev address in adev */
 	pdev = hns_dsaf_find_platform_device(acpi_fwnode_handle(args.adev));
+	if (!pdev) {
+		dev_err(mac_cb->dev, "mac%d mdio pdev is NULL\n",
+			mac_cb->mac_id);
+		return 0;
+	}
+
 	mii_bus = platform_get_drvdata(pdev);
+	if (!mii_bus) {
+		dev_err(mac_cb->dev,
+			"mac%d mdio is NULL, dsaf will probe again later\n",
+			mac_cb->mac_id);
+		return -EPROBE_DEFER;
+	}
+
 	rc = hns_mac_register_phydev(mii_bus, mac_cb, addr);
 	if (!rc)
 		dev_dbg(mac_cb->dev, "mac%d register phy addr:%d\n",
 			mac_cb->mac_id, addr);
+
+	return rc;
 }
 
 #define MAC_MEDIA_TYPE_MAX_LEN		16
@@ -793,7 +810,7 @@ static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
  *@np:device node
  * return: 0 --success, negative --fail
  */
-static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
+static int hns_mac_get_info(struct hns_mac_cb *mac_cb)
 {
 	struct device_node *np;
 	struct regmap *syscon;
@@ -903,7 +920,10 @@ static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
 			}
 		}
 	} else if (is_acpi_node(mac_cb->fw_port)) {
-		hns_mac_register_phy(mac_cb);
+		ret = hns_mac_register_phy(mac_cb);
+
+		if (ret)
+			return ret;
 	} else {
 		dev_err(mac_cb->dev, "mac%d cannot find phy node\n",
 			mac_cb->mac_id);
@@ -1065,6 +1085,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
 			dsaf_dev->mac_cb[port_id] = mac_cb;
 		}
 	}
+
 	/* init mac_cb for all port */
 	for (port_id = 0; port_id < max_port_num; port_id++) {
 		mac_cb = dsaf_dev->mac_cb[port_id];
@@ -1074,6 +1095,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
 		ret = hns_mac_get_cfg(dsaf_dev, mac_cb);
 		if (ret)
 			return ret;
+
 		ret = hns_mac_init_ex(mac_cb);
 		if (ret)
 			return ret;
-- 
1.9.1

[PATCH net-next 3/3] net: hns: fixed bug that skb used after kfree

[Yankejian]

From: lipeng <lipeng321@huawei.com>

There is KASAN warning which turn out it's a skb used after free:

    BUG: KASAN: use-after-free in hns_nic_net_xmit_hw+0x62c/0x940...
    [17659.112635]      alloc_debug_processing+0x18c/0x1a0
    [17659.117208]      __slab_alloc+0x52c/0x560
    [17659.120909]      kmem_cache_alloc_node+0xac/0x2c0
    [17659.125309]      __alloc_skb+0x6c/0x260
    [17659.128837]      tcp_send_ack+0x8c/0x280
    [17659.132449]      __tcp_ack_snd_check+0x9c/0xf0
    [17659.136587]      tcp_rcv_established+0x5a4/0xa70
    [17659.140899]      tcp_v4_do_rcv+0x27c/0x620
    [17659.144687]      tcp_prequeue_process+0x108/0x170
    [17659.149085]      tcp_recvmsg+0x940/0x1020
    [17659.152787]      inet_recvmsg+0x124/0x180
    [17659.156488]      sock_recvmsg+0x64/0x80
    [17659.160012]      SyS_recvfrom+0xd8/0x180
    [17659.163626]      __sys_trace_return+0x0/0x4
    [17659.167506] INFO: Freed in kfree_skbmem+0xa0/0xb0 age=23 cpu=1 pid=13
    [17659.174000]      free_debug_processing+0x1d4/0x2c0
    [17659.178486]      __slab_free+0x240/0x390
    [17659.182100]      kmem_cache_free+0x24c/0x270
    [17659.186062]      kfree_skbmem+0xa0/0xb0
    [17659.189587]      __kfree_skb+0x28/0x40
    [17659.193025]      napi_gro_receive+0x168/0x1c0
    [17659.197074]      hns_nic_rx_up_pro+0x58/0x90
    [17659.201038]      hns_nic_rx_poll_one+0x518/0xbc0
    [17659.205352]      hns_nic_common_poll+0x94/0x140
    [17659.209576]      net_rx_action+0x458/0x5e0
    [17659.213363]      __do_softirq+0x1b8/0x480
    [17659.217062]      run_ksoftirqd+0x64/0x80
    [17659.220679]      smpboot_thread_fn+0x224/0x310
    [17659.224821]      kthread+0x150/0x170
    [17659.228084]      ret_from_fork+0x10/0x40

    BUG: KASAN: use-after-free in hns_nic_net_xmit+0x8c/0xc0...
    [17751.080490]      __slab_alloc+0x52c/0x560
    [17751.084188]      kmem_cache_alloc+0x244/0x280
    [17751.088238]      __build_skb+0x40/0x150
    [17751.091764]      build_skb+0x28/0x100
    [17751.095115]      __alloc_rx_skb+0x94/0x150
    [17751.098900]      __napi_alloc_skb+0x34/0x90
    [17751.102776]      hns_nic_rx_poll_one+0x180/0xbc0
    [17751.107097]      hns_nic_common_poll+0x94/0x140
    [17751.111333]      net_rx_action+0x458/0x5e0
    [17751.115123]      __do_softirq+0x1b8/0x480
    [17751.118823]      run_ksoftirqd+0x64/0x80
    [17751.122437]      smpboot_thread_fn+0x224/0x310
    [17751.126575]      kthread+0x150/0x170
    [17751.129838]      ret_from_fork+0x10/0x40
    [17751.133454] INFO: Freed in kfree_skbmem+0xa0/0xb0 age=19 cpu=7 pid=43
    [17751.139951]      free_debug_processing+0x1d4/0x2c0
    [17751.144436]      __slab_free+0x240/0x390
    [17751.148051]      kmem_cache_free+0x24c/0x270
    [17751.152014]      kfree_skbmem+0xa0/0xb0
    [17751.155543]      __kfree_skb+0x28/0x40
    [17751.159022]      napi_gro_receive+0x168/0x1c0
    [17751.163074]      hns_nic_rx_up_pro+0x58/0x90
    [17751.167041]      hns_nic_rx_poll_one+0x518/0xbc0
    [17751.171358]      hns_nic_common_poll+0x94/0x140
    [17751.175585]      net_rx_action+0x458/0x5e0
    [17751.179373]      __do_softirq+0x1b8/0x480
    [17751.183076]      run_ksoftirqd+0x64/0x80
    [17751.186691]      smpboot_thread_fn+0x224/0x310
    [17751.190826]      kthread+0x150/0x170
    [17751.194093]      ret_from_fork+0x10/0x40

in drivers/net/ethernet/hisilicon/hns/hns_enet.c

    static netdev_tx_t hns_nic_net_xmit(struct sk_buff *skb,
                                        struct net_device *ndev)
    {
        struct hns_nic_priv *priv = netdev_priv(ndev);
        int ret;

        assert(skb->queue_mapping < ndev->ae_handle->q_num);
        ret = hns_nic_net_xmit_hw(ndev, skb,
                                  &tx_ring_data(priv, skb->queue_mapping));
        if (ret == NETDEV_TX_OK) {
                netif_trans_update(ndev);
                ndev->stats.tx_bytes += skb->len;
                ndev->stats.tx_packets++;
        }
         return (netdev_tx_t)ret;
    }

skb maybe freed in hns_nic_net_xmit_hw() and return NETDEV_TX_OK:

    out_err_tx_ok:

        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;

This patch fix this bug.

Reported-by: Jun He <hjat2005@huawei.com>
Signed-off-by: lipeng <lipeng321@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns/hns_enet.c | 22 ++++++++++------------
 drivers/net/ethernet/hisilicon/hns/hns_enet.h |  6 +++---
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
index fca37e2..1e04df6 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
@@ -300,9 +300,9 @@ static void fill_tso_desc(struct hnae_ring *ring, void *priv,
 			     mtu);
 }
 
-int hns_nic_net_xmit_hw(struct net_device *ndev,
-			struct sk_buff *skb,
-			struct hns_nic_ring_data *ring_data)
+netdev_tx_t hns_nic_net_xmit_hw(struct net_device *ndev,
+				struct sk_buff *skb,
+				struct hns_nic_ring_data *ring_data)
 {
 	struct hns_nic_priv *priv = netdev_priv(ndev);
 	struct hnae_ring *ring = ring_data->ring;
@@ -361,6 +361,10 @@ int hns_nic_net_xmit_hw(struct net_device *ndev,
 	dev_queue = netdev_get_tx_queue(ndev, skb->queue_mapping);
 	netdev_tx_sent_queue(dev_queue, skb->len);
 
+	netif_trans_update(ndev);
+	ndev->stats.tx_bytes += skb->len;
+	ndev->stats.tx_packets++;
+
 	wmb(); /* commit all data before submit */
 	assert(skb->queue_mapping < priv->ae_handle->q_num);
 	hnae_queue_xmit(priv->ae_handle->qs[skb->queue_mapping], buf_num);
@@ -1474,17 +1478,11 @@ static netdev_tx_t hns_nic_net_xmit(struct sk_buff *skb,
 				    struct net_device *ndev)
 {
 	struct hns_nic_priv *priv = netdev_priv(ndev);
-	int ret;
 
 	assert(skb->queue_mapping < ndev->ae_handle->q_num);
-	ret = hns_nic_net_xmit_hw(ndev, skb,
-				  &tx_ring_data(priv, skb->queue_mapping));
-	if (ret == NETDEV_TX_OK) {
-		netif_trans_update(ndev);
-		ndev->stats.tx_bytes += skb->len;
-		ndev->stats.tx_packets++;
-	}
-	return (netdev_tx_t)ret;
+
+	return hns_nic_net_xmit_hw(ndev, skb,
+				   &tx_ring_data(priv, skb->queue_mapping));
 }
 
 static int hns_nic_change_mtu(struct net_device *ndev, int new_mtu)
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.h b/drivers/net/ethernet/hisilicon/hns/hns_enet.h
index 5b412de..7bc6a6e 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.h
@@ -91,8 +91,8 @@ struct hns_nic_priv {
 void hns_nic_net_reset(struct net_device *ndev);
 void hns_nic_net_reinit(struct net_device *netdev);
 int hns_nic_init_phy(struct net_device *ndev, struct hnae_handle *h);
-int hns_nic_net_xmit_hw(struct net_device *ndev,
-			struct sk_buff *skb,
-			struct hns_nic_ring_data *ring_data);
+netdev_tx_t hns_nic_net_xmit_hw(struct net_device *ndev,
+				struct sk_buff *skb,
+				struct hns_nic_ring_data *ring_data);
 
 #endif	/**__HNS_ENET_H */
-- 
1.9.1

Re: [PATCH net-next 2/3] net: hns: support deferred probe when no mdio

[Matthias Brugger]

On 18/04/17 12:12, Yankejian wrote:
> From: lipeng <lipeng321@huawei.com>
>
> In the hip06 and hip07 SoCs, phy connect to mdio bus.The mdio
> module is probed with module_init, and, as such,
> is not guaranteed to probe before the HNS driver. So we need
> to support deferred probe.
>
> We check for probe deferral in the mac init, so we not init DSAF
> when there is no mdio, and free all resource, to later learn that
> we need to defer the probe.
>
> Signed-off-by: lipeng <lipeng321@huawei.com>

on which kernel version is this patch based?
I checked against next-20170420 and it does not apply.


> ---
>  drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c | 34 +++++++++++++++++++----
>  1 file changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
> index bdd8cdd..284ebfe 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
> @@ -735,6 +735,8 @@ static int hns_mac_init_ex(struct hns_mac_cb *mac_cb)
>  	rc = phy_device_register(phy);
>  	if (rc) {
>  		phy_device_free(phy);
> +		dev_err(&mdio->dev, "registered phy fail at address %i\n",
> +			addr);
>  		return -ENODEV;
>  	}
>
> @@ -745,7 +747,7 @@ static int hns_mac_init_ex(struct hns_mac_cb *mac_cb)
>  	return 0;
>  }
>
> -static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
> +static int hns_mac_register_phy(struct hns_mac_cb *mac_cb)
>  {
>  	struct acpi_reference_args args;
>  	struct platform_device *pdev;
> @@ -755,24 +757,39 @@ static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
>
>  	/* Loop over the child nodes and register a phy_device for each one */
>  	if (!to_acpi_device_node(mac_cb->fw_port))
> -		return;
> +		return 0;

Please return appropriate errno.

>
>  	rc = acpi_node_get_property_reference(
>  			mac_cb->fw_port, "mdio-node", 0, &args);
>  	if (rc)
> -		return;
> +		return 0;

Please return appropriate errno.

>
>  	addr = hns_mac_phy_parse_addr(mac_cb->dev, mac_cb->fw_port);
>  	if (addr < 0)
> -		return;
> +		return 0;

Shouldn't we just error out here by returning addr?

>
>  	/* dev address in adev */
>  	pdev = hns_dsaf_find_platform_device(acpi_fwnode_handle(args.adev));
> +	if (!pdev) {
> +		dev_err(mac_cb->dev, "mac%d mdio pdev is NULL\n",
> +			mac_cb->mac_id);
> +		return 0;

Please return appropriate errno.

Regards,
Matthias

> +	}
> +
>  	mii_bus = platform_get_drvdata(pdev);
> +	if (!mii_bus) {
> +		dev_err(mac_cb->dev,
> +			"mac%d mdio is NULL, dsaf will probe again later\n",
> +			mac_cb->mac_id);
> +		return -EPROBE_DEFER;
> +	}
> +
>  	rc = hns_mac_register_phydev(mii_bus, mac_cb, addr);
>  	if (!rc)
>  		dev_dbg(mac_cb->dev, "mac%d register phy addr:%d\n",
>  			mac_cb->mac_id, addr);
> +
> +	return rc;
>  }
>
>  #define MAC_MEDIA_TYPE_MAX_LEN		16
> @@ -793,7 +810,7 @@ static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
>   *@np:device node
>   * return: 0 --success, negative --fail
>   */
> -static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
> +static int hns_mac_get_info(struct hns_mac_cb *mac_cb)
>  {
>  	struct device_node *np;
>  	struct regmap *syscon;
> @@ -903,7 +920,10 @@ static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
>  			}
>  		}
>  	} else if (is_acpi_node(mac_cb->fw_port)) {
> -		hns_mac_register_phy(mac_cb);
> +		ret = hns_mac_register_phy(mac_cb);
> +
> +		if (ret)
> +			return ret;
>  	} else {
>  		dev_err(mac_cb->dev, "mac%d cannot find phy node\n",
>  			mac_cb->mac_id);
> @@ -1065,6 +1085,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
>  			dsaf_dev->mac_cb[port_id] = mac_cb;
>  		}
>  	}
> +
>  	/* init mac_cb for all port */
>  	for (port_id = 0; port_id < max_port_num; port_id++) {
>  		mac_cb = dsaf_dev->mac_cb[port_id];
> @@ -1074,6 +1095,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
>  		ret = hns_mac_get_cfg(dsaf_dev, mac_cb);
>  		if (ret)
>  			return ret;
> +
>  		ret = hns_mac_init_ex(mac_cb);
>  		if (ret)
>  			return ret;
>

Re: [PATCH net-next 2/3] net: hns: support deferred probe when no mdio

[lipeng (Y)]

On 2017/4/20 19:13, Matthias Brugger wrote:
> On 18/04/17 12:12, Yankejian wrote:
>> From: lipeng <lipeng321@huawei.com>
>>
>> In the hip06 and hip07 SoCs, phy connect to mdio bus.The mdio
>> module is probed with module_init, and, as such,
>> is not guaranteed to probe before the HNS driver. So we need
>> to support deferred probe.
>>
>> We check for probe deferral in the mac init, so we not init DSAF
>> when there is no mdio, and free all resource, to later learn that
>> we need to defer the probe.
>>
>> Signed-off-by: lipeng <lipeng321@huawei.com>
>
> on which kernel version is this patch based?
> I checked against next-20170420 and it does not apply.
>

Will refloat this patchset on net.

thanks.
lipeng
>
>> ---
>>  drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c | 34 
>> +++++++++++++++++++----
>>  1 file changed, 28 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c 
>> b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
>> index bdd8cdd..284ebfe 100644
>> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
>> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c
>> @@ -735,6 +735,8 @@ static int hns_mac_init_ex(struct hns_mac_cb 
>> *mac_cb)
>>      rc = phy_device_register(phy);
>>      if (rc) {
>>          phy_device_free(phy);
>> +        dev_err(&mdio->dev, "registered phy fail at address %i\n",
>> +            addr);
>>          return -ENODEV;
>>      }
>>
>> @@ -745,7 +747,7 @@ static int hns_mac_init_ex(struct hns_mac_cb 
>> *mac_cb)
>>      return 0;
>>  }
>>
>> -static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
>> +static int hns_mac_register_phy(struct hns_mac_cb *mac_cb)
>>  {
>>      struct acpi_reference_args args;
>>      struct platform_device *pdev;
>> @@ -755,24 +757,39 @@ static void hns_mac_register_phy(struct 
>> hns_mac_cb *mac_cb)
>>
>>      /* Loop over the child nodes and register a phy_device for each 
>> one */
>>      if (!to_acpi_device_node(mac_cb->fw_port))
>> -        return;
>> +        return 0;
>
> Please return appropriate errno.
>
>>
>>      rc = acpi_node_get_property_reference(
>>              mac_cb->fw_port, "mdio-node", 0, &args);
>>      if (rc)
>> -        return;
>> +        return 0;
>
> Please return appropriate errno.
>
>>
>>      addr = hns_mac_phy_parse_addr(mac_cb->dev, mac_cb->fw_port);
>>      if (addr < 0)
>> -        return;
>> +        return 0;
>
> Shouldn't we just error out here by returning addr?
>
>>
>>      /* dev address in adev */
>>      pdev = 
>> hns_dsaf_find_platform_device(acpi_fwnode_handle(args.adev));
>> +    if (!pdev) {
>> +        dev_err(mac_cb->dev, "mac%d mdio pdev is NULL\n",
>> +            mac_cb->mac_id);
>> +        return 0;
>
> Please return appropriate errno.
>
> Regards,
> Matthias
>
>> +    }
>> +
>>      mii_bus = platform_get_drvdata(pdev);
>> +    if (!mii_bus) {
>> +        dev_err(mac_cb->dev,
>> +            "mac%d mdio is NULL, dsaf will probe again later\n",
>> +            mac_cb->mac_id);
>> +        return -EPROBE_DEFER;
>> +    }
>> +
>>      rc = hns_mac_register_phydev(mii_bus, mac_cb, addr);
>>      if (!rc)
>>          dev_dbg(mac_cb->dev, "mac%d register phy addr:%d\n",
>>              mac_cb->mac_id, addr);
>> +
>> +    return rc;
>>  }
>>
>>  #define MAC_MEDIA_TYPE_MAX_LEN        16
>> @@ -793,7 +810,7 @@ static void hns_mac_register_phy(struct 
>> hns_mac_cb *mac_cb)
>>   *@np:device node
>>   * return: 0 --success, negative --fail
>>   */
>> -static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
>> +static int hns_mac_get_info(struct hns_mac_cb *mac_cb)
>>  {
>>      struct device_node *np;
>>      struct regmap *syscon;
>> @@ -903,7 +920,10 @@ static int  hns_mac_get_info(struct hns_mac_cb 
>> *mac_cb)
>>              }
>>          }
>>      } else if (is_acpi_node(mac_cb->fw_port)) {
>> -        hns_mac_register_phy(mac_cb);
>> +        ret = hns_mac_register_phy(mac_cb);
>> +
>> +        if (ret)
>> +            return ret;
>>      } else {
>>          dev_err(mac_cb->dev, "mac%d cannot find phy node\n",
>>              mac_cb->mac_id);
>> @@ -1065,6 +1085,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
>>              dsaf_dev->mac_cb[port_id] = mac_cb;
>>          }
>>      }
>> +
>>      /* init mac_cb for all port */
>>      for (port_id = 0; port_id < max_port_num; port_id++) {
>>          mac_cb = dsaf_dev->mac_cb[port_id];
>> @@ -1074,6 +1095,7 @@ int hns_mac_init(struct dsaf_device *dsaf_dev)
>>          ret = hns_mac_get_cfg(dsaf_dev, mac_cb);
>>          if (ret)
>>              return ret;
>> +
>>          ret = hns_mac_init_ex(mac_cb);
>>          if (ret)
>>              return ret;
>>
>
> .
>