6.6-stable review patch. If anyone has any objections, please let me know.
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From: Horatiu Vultur horatiu.vultur@microchip.com
[ Upstream commit 57a92d14659df3e7e7e0052358c8cc68bbbc3b5e ]
We have noticed that when PHY timestamping is enabled, L2 frames seems to be modified by changing two 2 bytes with a value of 0. The place were these 2 bytes seems to be random(or I couldn't find a pattern). In most of the cases the userspace can ignore these frames but if for example those 2 bytes are in the correction field there is nothing to do. This seems to happen when configuring the HW for IPv4 even that the flow is not enabled. These 2 bytes correspond to the UDPv4 checksum and once we don't enable clearing the checksum when using L2 frames then the frame doesn't seem to be changed anymore.
Fixes: 7d272e63e0979d ("net: phy: mscc: timestamping and PHC support") Signed-off-by: Horatiu Vultur horatiu.vultur@microchip.com Link: https://patch.msgid.link/20250523082716.2935895-1-horatiu.vultur@microchip.c... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/mscc/mscc_ptp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/mscc/mscc_ptp.c b/drivers/net/phy/mscc/mscc_ptp.c index af44b01f3d383..7e7ce79eadffb 100644 --- a/drivers/net/phy/mscc/mscc_ptp.c +++ b/drivers/net/phy/mscc/mscc_ptp.c @@ -943,7 +943,9 @@ static int vsc85xx_ip1_conf(struct phy_device *phydev, enum ts_blk blk, /* UDP checksum offset in IPv4 packet * according to: https://tools.ietf.org/html/rfc768 */ - val |= IP1_NXT_PROT_UDP_CHKSUM_OFF(26) | IP1_NXT_PROT_UDP_CHKSUM_CLEAR; + val |= IP1_NXT_PROT_UDP_CHKSUM_OFF(26); + if (enable) + val |= IP1_NXT_PROT_UDP_CHKSUM_CLEAR; vsc85xx_ts_write_csr(phydev, blk, MSCC_ANA_IP1_NXT_PROT_UDP_CHKSUM, val);