Hello:
This series was applied to netdev/net-next.git (main)
by Jakub Kicinski [off-list ref]:
On Tue, 13 Oct 2026 11:45:01 +0000 you wrote:
On the Renesas RZ/V2H platform, which has two dwmac4 controllers, we
observed sporadic iperf3 TCP TX failures on one of the controllers, with
throughput dropping from >900Mbit/s to ~1Mbit/s due to TX underflows and
the resulting retransmissions.
Commit 3a6c12a0c6c3 ("net: stmmac: bump tc when get underflow error from
DMA descriptor") made dwmac4 raise the DMA threshold of the queues that
report TX underflows, by increasing a global module parameter 'tc'.
However, this logic does not work correctly across multiple queues and
controllers, and can leave the TX DMA threshold stuck at 64 bytes.
[...]
Here is the summary with links:
- [net,1/2] net: stmmac: Track the TX DMA threshold per queue
https://git.kernel.org/netdev/net-next/c/9dd534187819
- [net,2/2] net: stmmac: Report the TX DMA threshold per queue
https://git.kernel.org/netdev/net-next/c/aee7b59e6e7b
You are awesome, thank you!
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