[PATCH net v3] net: airoha: fix BQL underflow in shared QDMA TX ring

[patchwork-bot+netdevbpf at kernel.org]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba at kernel.org>:

On Sat, 20 Jun 2026 17:04:51 +0200 you wrote:
> When multiple netdevs share a QDMA TX ring and one device is stopped,
> netdev_tx_reset_subqueue() zeroes that device's BQL counters while its
> pending skbs remain in the shared HW TX ring. When NAPI later completes
> those skbs via netdev_tx_completed_queue(), the already-zeroed
> dql->num_queued counter underflows.
> 
> Fix the issue:
> - Remove netdev_tx_reset_subqueue() from airoha_dev_stop() so pending
>   skbs are completed naturally by NAPI with proper BQL accounting.
> - Rework airoha_qdma_tx_cleanup() to disable TX DMA, flush BQL
>   counters, DMA-unmap and free all pending skbs while skb->dev
>   references are still valid. Use a per-queue flushing flag checked
>   under q->lock in airoha_dev_xmit() to prevent races between teardown
>   and transmit. Call airoha_qdma_stop_napi() before
>   airoha_qdma_tx_cleanup() at the call sites.
> - Move DMA engine start into probe. Split DMA teardown so TX DMA is
>   disabled in airoha_qdma_tx_cleanup() and RX DMA in
>   airoha_qdma_cleanup().
> - Remove qdma->users counter since DMA lifetime is now tied to
>   probe/cleanup rather than per-netdev open/stop.
> 
> [...]

Here is the summary with links:
  - [net,v3] net: airoha: fix BQL underflow in shared QDMA TX ring
    https://git.kernel.org/netdev/net/c/611709830945

You are awesome, thank you!
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