[PATCH net-next v4 1/2] net: stmmac: dwxgmac2: add XGMAC timestamp interrupt support

Maxime Chevallier maxime.chevallier at bootlin.com
Thu Sep 3 03:03:01 PDT 2026


Hi,

On 9/2/26 15:14, Zxyan Zhu wrote:
> DWXGMAC2 uses XGMAC_TIMESTAMP_STATUS at offset 0xd20, while the
> generic stmmac PTP handler reads the dwmac4 offset GMAC_TIMESTAMP_STATUS
> (0xb20).  Before this change, the DWXGMAC2 and DWXLGMAC2 hwif entries
> used &stmmac_ptp, whose timestamp_interrupt callback read the wrong
> register and whose config_hw_tstamping callback never enabled the
> XGMAC timestamp interrupt (XGMAC_TSIE was not in XGMAC_INT_DEFAULT_EN).
> As a result, auxiliary snapshot events were never reported on XGMAC
> platforms.
> 
> Add a dedicated DWXGMAC2 timestamp interrupt handler that:
> - reads XGMAC_TIMESTAMP_STATUS before checking
>   STMMAC_FLAG_EXT_SNAPSHOT_EN, so that the timestamp interrupt status is
>   cleared even when auxiliary snapshots are disabled
> - derives the pending auxiliary snapshot count from the persistent
>   ATSNS field instead of the transient AUXTSTRIG status bit
> - generates the corresponding PTP_CLOCK_EXTTS events
> 
> Also enable XGMAC_TSIE in XGMAC_INT_DEFAULT_EN and hook the new
> handler into the DWXGMAC2 and DWXLGMAC2 hwif entries.
> 
> Signed-off-by: Zxyan Zhu <zxyan0222 at gmail.com>

Reviewed-by: Maxime Chevallier <maxime.chevallier at bootlin.com>

Maxime




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