From 6b3336ab425cc346b48a9d6772631b60b9a9563c Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu@redhat.com>
Date: Mon, 3 Mar 2025 08:38:28 +0800
Subject: [PATCH] Fallback to get NIC driver by
 /sys/class/net/NIC/device/driver/module

Resolves: https://issues.redhat.com/browse/RHEL-67131
Conflict: Upstream uses a different path dracut/99kdumpbase/module-setup.sh.

Upstream Status: git@github.com:rhkdump/kdump-utils.git

commit 821a5e648dcb72d89065078e0cadb58a5313b183
Author: Coiby Xu <coxu@redhat.com>
Date:   Thu Nov 28 18:07:49 2024 +0800

    Fallback to get NIC driver by /sys/class/net/NIC/device/driver/module

    Resolves: https://issues.redhat.com/browse/RHEL-67131

    Some drivers like dwmac_tegra may report its name incorrectly. So
    fallback to /sys/class/net/NIC/device/driver/modul to address these
    cases. Note this method only for physical NICs i.e it doesn't work for
    virtual NICs like bonding NIC.

    Suggested-by: Michal Schmidt <mschmidt@redhat.com>
    Signed-off-by: Coiby Xu <coxu@redhat.com>

Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 dracut-module-setup.sh | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 8b67c86..59b38af 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -380,7 +380,27 @@ EOF
 }
 
 _get_nic_driver() {
-    ethtool -i "$1" | sed -n -E "s/driver: (.*)/\1/p"
+    local _driver
+
+    _driver=$(ethtool -i "$1" | sed -n -E "s/driver: (.*)/\1/p")
+
+    if [[ $_driver == "802.1Q VLAN Support" ]]; then
+        # ethtool somehow doesn't return the driver name for a VLAN NIC
+        _driver=8021q
+    fi
+
+    if ! modinfo "$_driver" &> /dev/null; then
+        # Fallback to get NIC driver by /sys/class/net/NIC/device/driver/module
+        # as some drivers like dwmac_tegra may report its name incorrectly.
+        # Note this method only for physical NICs i.e it doesn't work for
+        # virtual NICs like bonding NIC
+        _driver=$(basename "$(readlink -f /sys/class/net/"$1"/device/driver/module)")
+        if ! modinfo "$_driver" &> /dev/null; then
+            derror "Failed to find the driver for $1 ($_driver doesnt exist)"
+        fi
+    fi
+
+    echo -n "$_driver"
 }
 
 _get_hpyerv_physical_driver() {
@@ -412,10 +432,7 @@ kdump_install_nic_driver() {
             exit 1
         fi
 
-        if [[ $_driver == "802.1Q VLAN Support" ]]; then
-            # ethtool somehow doesn't return the driver name for a VLAN NIC
-            _driver=8021q
-        elif [[ $_driver == "team" ]]; then
+        if [[ $_driver == "team" ]]; then
             # install the team mode drivers like team_mode_roundrobin.ko as well
             _driver='=drivers/net/team'
         elif [[ $_driver == "hv_netvsc" ]]; then