Re: [PATCH net v2] net: stmmac: Fix E2E delay mechanism

From: G Thomas, Rohan
Date: Tue Dec 09 2025 - 07:27:32 EST


Hi Paolo,

On 12/4/2025 3:28 PM, Paolo Abeni wrote:
On 11/29/25 4:07 AM, Rohan G Thomas wrote:
For E2E delay mechanism, "received DELAY_REQ without timestamp" error
messages show up for dwmac v3.70+ and dwxgmac IPs.

This issue affects socfpga platforms, Agilex7 (dwmac 3.70) and
Agilex5 (dwxgmac). According to the databook, to enable timestamping
for all events, the SNAPTYPSEL bits in the MAC_Timestamp_Control
register must be set to 2'b01, and the TSEVNTENA bit must be cleared
to 0'b0.

Commit 3cb958027cb8 ("net: stmmac: Fix E2E delay mechanism") already
addresses this problem for all dwmacs above version v4.10. However,
same holds true for v3.70 and above, as well as for dwxgmac. Updates
the check accordingly.

Fixes: 14f347334bf2 ("net: stmmac: Correctly take timestamp for PTPv2")
Fixes: f2fb6b6275eb ("net: stmmac: enable timestamp snapshot for required PTP packets in dwmac v5.10a")
Fixes: 3cb958027cb8 ("net: stmmac: Fix E2E delay mechanism")
Signed-off-by: Rohan G Thomas <rohan.g.thomas@xxxxxxxxxx>
---
v1 -> v2:
- Rebased patch to net tree
- Replace core_type with has_xgmac
- Nit changes in the commit message
- Link: https://lore.kernel.org/all/20251125-ext-ptp-fix-v1-1-83f9f069cb36@xxxxxxxxxx/

Given there is some uncertain WRT the exact oldest version to be used,
it would be great to have some 3rd party testing/feedback on this. Let's
wait a little more.

Thanks for reviewing the patch. Sure, will wait for additional feedback.


Thanks,

Paolo


Best Regards,
Rohan