Re: [PATCH net-next v3 2/2] net: stmmac: dwmac-socfpga: mask XGMAC_TSIE during cross-timestamp

[Andrew Lunn]

On Tue, Aug 18, 2026 at 09:27:22PM +0800, Zxyan Zhu wrote:
> The Agilex5 smtg_crosststamp() handler arms an internal auxiliary
> snapshot, toggles GPO0 and then polls XGMAC_INT_STATUS for TSIS in
> process context to learn that the snapshot is ready.
> 
> Once XGMAC_TSIE is unmasked (done by a companion change that enables it
> in XGMAC_INT_DEFAULT_EN), the DWXGMAC2 timestamp interrupt handler runs
> from hardirq on every timestamp event and clears TSIS by reading
> XGMAC_TIMESTAMP_STATUS.  That read can win the race against the poll
> loop, which then times out and makes PTP_SYS_OFFSET_PRECISE fail with
> "Wait for time sync operation timeout".
> 
> Mask XGMAC_TSIE around the snapshot trigger and FIFO read so the hardirq
> handler cannot clear TSIS while smtg_crosststamp() owns it, and restore
> it on every return path.

Did you look at the other system which implement crosststamp?
dwmac-intel.c? Does it need similar changes?

	Andrew