[PATCH v2 net 2/2] net: hibmcge: fix wrong ndo.open() after reset fail issue.

[Jijie Shao]

If the driver reset fails, it may not work properly.
Therefore, the ndo.open() operation should be rejected.

In this patch, the driver calls netif_device_detach()
before the reset and calls netif_device_attach()
after the reset succeeds. If the reset fails,
netif_device_attach() is not called. Therefore,
netdev does not present and cannot be opened.

If reset fails, only the PCI reset (via sysfs)
can be used to attempt recovery.

Fixes: 3f5a61f6d504 ("net: hibmcge: Add reset supported in this module")
Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx>
---
ChangeLog:
v1 -> v2:
  - Use netif_device_detach() to block netdev callbacks after reset fails, suggested by Jakub.
  v1: https://lore.kernel.org/all/20250430093127.2400813-1-shaojijie@xxxxxxxxxx/
---
 drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c
index a0bcfb5a713d..ff3295b60a69 100644
--- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c
+++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c
@@ -61,6 +61,8 @@ static int hbg_reset_prepare(struct hbg_priv *priv, enum hbg_reset_type type)
 		return -EBUSY;
 	}
 
+	netif_device_detach(priv->netdev);
+
 	priv->reset_type = type;
 	set_bit(HBG_NIC_STATE_RESETTING, &priv->state);
 	clear_bit(HBG_NIC_STATE_RESET_FAIL, &priv->state);
@@ -91,6 +93,8 @@ static int hbg_reset_done(struct hbg_priv *priv, enum hbg_reset_type type)
 		return ret;
 	}
 
+	netif_device_attach(priv->netdev);
+
 	dev_info(&priv->pdev->dev, "reset done\n");
 	return ret;
 }
@@ -117,16 +121,13 @@ void hbg_err_reset(struct hbg_priv *priv)
 	if (running)
 		dev_close(priv->netdev);
 
-	hbg_reset(priv);
-
-	/* in hbg_pci_err_detected(), we will detach first,
-	 * so we need to attach before open
-	 */
-	if (!netif_device_present(priv->netdev))
-		netif_device_attach(priv->netdev);
+	if (hbg_reset(priv))
+		goto err_unlock;
 
 	if (running)
 		dev_open(priv->netdev, NULL);
+
+err_unlock:
 	rtnl_unlock();
 }
 
@@ -160,7 +161,6 @@ static pci_ers_result_t hbg_pci_err_slot_reset(struct pci_dev *pdev)
 	pci_save_state(pdev);
 
 	hbg_err_reset(priv);
-	netif_device_attach(netdev);
 	return PCI_ERS_RESULT_RECOVERED;
 }
 
-- 
2.33.0