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

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski [off-list ref]:

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!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html