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* [PATCH 0/5] Fix GBETH TX scheduling policy for RZ/{V2H, V2N, G3E, T2H, N2H}
@ 2026-07-22  8:53 Ovidiu Panait
  2026-07-22  8:53 ` [PATCH 1/5] arm64: dts: renesas: r9a09g057: Switch GBETH TX queue scheduling to WRR Ovidiu Panait
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Ovidiu Panait @ 2026-07-22  8:53 UTC (permalink / raw)
  To: geert+renesas, magnus.damm, robh, krzk+dt, conor+dt,
	prabhakar.mahadev-lad.rj, biju.das.jz
  Cc: linux-renesas-soc, devicetree, linux-kernel, Ovidiu Panait

This series switches the GBETH TX scheduling policy to
Weighted-Round-Robin (WRR) on RZ/V2H, RZ/V2N, RZ/G3E, RZ/T2H and RZ/N2H
SoCs.

Since the GBETH nodes don't currently specify a TX scheduling policy,
stmmac falls back to Strict Priority. In that configuration the highest
priority queue gets all the traffic and starves the others under load.

Under sustained UDP TX load with multiple data streams, this starvation
triggers adapter resets due to TX queue timeouts:

  iperf3 -c <ip> -i0 -t60 --bind-dev end0 -u -b0 -P4
  end0: NETDEV WATCHDOG: CPU: 1: transmit queue 1 timed out 5228 ms
  end0: Reset adapter.

Investigation showed that only the highest priority queue advances while
the others stall for more than 5 seconds, causing the netdev watchdog
reset.

Ovidiu Panait (5):
  arm64: dts: renesas: r9a09g057: Switch GBETH TX queue scheduling to
    WRR
  arm64: dts: renesas: r9a09g056: Switch GBETH TX queue scheduling to
    WRR
  arm64: dts: renesas: r9a09g047: Switch GBETH TX queue scheduling to
    WRR
  arm64: dts: renesas: r9a09g077: Switch GBETH TX queue scheduling to
    WRR
  arm64: dts: renesas: r9a09g078: Switch GBETH TX queue scheduling to
    WRR

 arch/arm64/boot/dts/renesas/r9a09g047.dtsi | 10 ++++++++
 arch/arm64/boot/dts/renesas/r9a09g056.dtsi | 10 ++++++++
 arch/arm64/boot/dts/renesas/r9a09g057.dtsi | 10 ++++++++
 arch/arm64/boot/dts/renesas/r9a09g077.dtsi | 27 ++++++++++++++++++++++
 arch/arm64/boot/dts/renesas/r9a09g087.dtsi | 27 ++++++++++++++++++++++
 5 files changed, 84 insertions(+)

-- 
2.34.1


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2026-07-22  9:07 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-22  8:53 [PATCH 0/5] Fix GBETH TX scheduling policy for RZ/{V2H, V2N, G3E, T2H, N2H} Ovidiu Panait
2026-07-22  8:53 ` [PATCH 1/5] arm64: dts: renesas: r9a09g057: Switch GBETH TX queue scheduling to WRR Ovidiu Panait
2026-07-22  8:53 ` [PATCH 2/5] arm64: dts: renesas: r9a09g056: " Ovidiu Panait
2026-07-22  9:04   ` sashiko-bot
2026-07-22  8:53 ` [PATCH 3/5] arm64: dts: renesas: r9a09g047: " Ovidiu Panait
2026-07-22  8:53 ` [PATCH 4/5] arm64: dts: renesas: r9a09g077: " Ovidiu Panait
2026-07-22  9:07   ` sashiko-bot
2026-07-22  8:53 ` [PATCH 5/5] arm64: dts: renesas: r9a09g078: " Ovidiu Panait

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