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

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

On 7/27/26 04:25, muhammad.nazim.amirul.nazle.asmade@altera.com wrote:
> From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>
> 
> 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@altera.com>
> Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>

Given the original discussions that took place, it seems that this is
the correct fix. As Russell suggest, we need some timestamping selftest
to make it easy to find regressions with this kind of patches, but
I've experimented with stmmac selftests over the weekend and they are
in a sorry state right now...

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

Maxime