6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aakash Menon <aakash.r.menon@xxxxxxxxx>
[ Upstream commit 151ac45348afc5b56baa584c7cd4876addf461ff ]
Bit 270-271 are occasionally unexpectedly set by the hardware. This issue
was observed with 10G SFPs causing huge time errors (> 30ms) in PTP. Only
30 bits are needed for the nanosecond part of the timestamp, clear 2 most
significant bits before extracting timestamp from the internal frame
header.
Fixes: 70dfe25cd866 ("net: sparx5: Update extraction/injection for timestamping")
Signed-off-by: Aakash Menon <aakash.menon@xxxxxxxxxxxxx>
Reviewed-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/microchip/sparx5/sparx5_packet.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
index ac7e1cffbcecf..dcf2e342fc14a 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
@@ -45,8 +45,12 @@ void sparx5_ifh_parse(u32 *ifh, struct frame_info *info)
fwd = (fwd >> 5);
info->src_port = FIELD_GET(GENMASK(7, 1), fwd);
+ /*
+ * Bit 270-271 are occasionally unexpectedly set by the hardware,
+ * clear bits before extracting timestamp
+ */
info->timestamp =
- ((u64)xtr_hdr[2] << 24) |
+ ((u64)(xtr_hdr[2] & GENMASK(5, 0)) << 24) |
((u64)xtr_hdr[3] << 16) |
((u64)xtr_hdr[4] << 8) |
((u64)xtr_hdr[5] << 0);
--
2.43.0
