Re: [PATCH net v4 00/15] net: stmmac: preserve datapath state across MTU and resume failures
From: Maxime Chevallier
Date: Sat Sep 26 2026 - 12:03:32 EST
Hello James,
On 9/26/26 17:48, James Hilliard wrote:
> Keep the stmmac datapath coherent after failed MTU changes or hardware
> resume without changing the interface's administrative state. Retain the
> working MTU configuration for rollback, and allow ordinary down/up recovery
> when hardware cannot be restored.
>
> The fifteen patches put independent fixes and lifetime prerequisites ahead
> of the retained-ring MTU transaction:
>
> 1. Correct the WoL/safety IRQ unwind order.
> 2. Reuse the MDIO reset GPIO across repeated resets.
> 3. Allow phylink_stop() to finish a suspended instance.
> 4. Freeze deferred AF_XDP pool teardown before device system suspend.
> 5. Serialize PHC changes and cache reset-sensitive timestamp settings.
> 6. Keep normal-size MTU changes running, including supported AF_XDP MTUs.
> 7. Unwind partial DMA allocations and fix saved RX skb ownership.
> 8. Keep DMA configurations and IRQ contexts at stable addresses, and
> drain timer producers before cancelling their timers.
> 9. Track datapath and power ownership across MTU, XDP and ethtool reopen
> failures, including noirq clock handling and unpowered-access guards.
> 10. Use the tracked restart for XSK pool changes.
> 11. Restore TC filters, steering, preemption mapping and EST before DMA.
> 12. Allow independent references to AF_XDP DMA mappings and UMEM pages.
> 13. Retain DMA memory until hardware confirms shutdown or reset.
> 14. Prepare device-local interrupt masking and DMA-handler quiescence.
> 15. Retain rings and IRQ registrations across jumbo MTU replacement.
Please look at the mailing list, several of these patches are already being
worked on and have gone through multiple iterations and reviews.
Thanks :)
Maxime