In ixp4xx_get_ts_info() ixp46x_ptp_find() is called unconditionally despite this feature only existing on ixp46x, leading to the following splat from tcpdump: root@OpenWrt:~# tcpdump -vv -X -i eth0 (...) Unable to handle kernel NULL pointer dereference at virtual address 00000238 when read (...) Call trace: ptp_clock_index from ixp46x_ptp_find+0x1c/0x38 ixp46x_ptp_find from ixp4xx_get_ts_info+0x4c/0x64 ixp4xx_get_ts_info from __ethtool_get_ts_info+0x90/0x108 __ethtool_get_ts_info from __dev_ethtool+0xa00/0x2648 __dev_ethtool from dev_ethtool+0x160/0x234 dev_ethtool from dev_ioctl+0x2cc/0x460 dev_ioctl from sock_ioctl+0x1ec/0x524 sock_ioctl from sys_ioctl+0x51c/0xa94 sys_ioctl from ret_fast_syscall+0x0/0x44 (...) Segmentation fault Check for ixp46x in ixp46x_ptp_find() before trying to set up PTP to avoid this. Fixes: 9055a2f59162 ("ixp4xx_eth: make ptp support a platform driver") Signed-off-by: Linus Walleij --- Changes in v2: - Use the correct Fixes-tag. - Move check to ixp46x_ptp_find() to simplify things. - Link to v1: https://lore.kernel.org/r/20260116-ixp4xx-fix-ethernet-v1-1-9ab3b411c77e@kernel.org --- drivers/net/ethernet/xscale/ixp4xx_eth.c | 5 +---- drivers/net/ethernet/xscale/ptp_ixp46x.c | 3 +++ 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c index e1e7f65553e7..b0faa0f1780d 100644 --- a/drivers/net/ethernet/xscale/ixp4xx_eth.c +++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c @@ -403,15 +403,12 @@ static int ixp4xx_hwtstamp_set(struct net_device *netdev, int ret; int ch; - if (!cpu_is_ixp46x()) - return -EOPNOTSUPP; - if (!netif_running(netdev)) return -EINVAL; ret = ixp46x_ptp_find(&port->timesync_regs, &port->phc_index); if (ret) - return ret; + return -EOPNOTSUPP; ch = PORT2CHANNEL(port); regs = port->timesync_regs; diff --git a/drivers/net/ethernet/xscale/ptp_ixp46x.c b/drivers/net/ethernet/xscale/ptp_ixp46x.c index 94203eb46e6b..93c64db22a69 100644 --- a/drivers/net/ethernet/xscale/ptp_ixp46x.c +++ b/drivers/net/ethernet/xscale/ptp_ixp46x.c @@ -232,6 +232,9 @@ static struct ixp_clock ixp_clock; int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index) { + if (!cpu_is_ixp46x()) + return -ENODEV; + *regs = ixp_clock.regs; *phc_index = ptp_clock_index(ixp_clock.ptp_clock); --- base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b change-id: 20260116-ixp4xx-fix-ethernet-4fa36d900ccc Best regards, -- Linus Walleij