> -----Original Message----- > From: Intel-wired-lan <[email protected]> On Behalf Of > Grzegorz Nitka > Sent: Thursday, November 27, 2025 1:26 AM > To: [email protected] > Cc: Loktionov, Aleksandr <[email protected]>; > [email protected]; Nguyen, Anthony L <[email protected]>; > Kitszel, Przemyslaw > <[email protected]> > Subject: [Intel-wired-lan] [PATCH iwl-net] ice: fix missing TX timestamps > interrupts on E825 devices > > Modify PTP (Precision Time Protocol) configuration on link down flow. > Previously, PHY_REG_TX_OFFSET_READY register was cleared in such case. > This register is used to determine if the timestamp is valid or not on > the hardware side. > However, there is a possibility that there is still the packet in the > HW queue which originally was supposed to be timestamped but the link > is already down and given register is cleared. > This potentially might lead to the situation in which that 'delayed' > packet's timestamp is treated as invalid one when the link is up > again. > This in turn leads to the situation in which the driver is not able to > effectively clean timestamp memory and interrupt configuration. > From the hardware perspective, that 'old' interrupt was not handled > properly and even if new timestamp packets are processed, no new > interrupts is generated. As a result, providing timestamps to the user > applications (like ptp4l) is not possible. > The solution for this problem is implemented at the driver level rather > than the firmware, and maintains the tx_ready bit high, even during > link down events. This avoids entering a potential inconsistent state > between the driver and the timestamp hardware. > > Testing hints: > - run PTP traffic at higher rate (like 16 PTP messages per second) > - observe ptp4l behaviour at the client side in the following > conditions: > a) trigger link toggle events. It needs to be physiscal > link down/up events > b) link speed change > In all above cases, PTP processing at ptp4l application should resume > always. In failure case, the following permanent error message in ptp4l > log was observed: > controller-0 ptp4l: err [6175.116] ptp4l-legacy timed out while polling > for tx timestamp > > Fixes: 7cab44f1c35f ("ice: Introduce ETH56G PHY model for E825C products") > Reviewed-by: Aleksandr Loktionov <[email protected]> > Signed-off-by: Grzegorz Nitka <[email protected]> > --- > drivers/net/ethernet/intel/ice/ice_ptp.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-)
Tested-by: Sunitha Mekala <[email protected]> (A Contingent worker at Intel)
