[RFC 1/2] wifi: mt76: disable NAPI before deleting in dma_cleanup

[Devin Wittmayer]

On 9/16/26 13:47, Ben Greear wrote:
> +		napi_disable(&dev->napi[i]);
>  		netif_napi_del(&dev->napi[i]);

Ben,

The warning and the softirqd spin are both real, and your 2/2 looks like
the right place for them.

On 1/2 there is a snag. mt7921e and mt7925e already stop RX themselves,
and they do it early:

	mt76_unregister_device()
	napi_disable() on each rx queue
	tx_token_put()
	mt792x_dma_cleanup()

It has to be early. A poll still in flight can come back with a transmit
status and take an entry out of the table tx_token_put() is tearing
down. By the time the shared cleanup runs RX is already stopped, so a
second disable there just sits:

	task in D state, refcount -1
	napi_disable_locked <- mt76_dma_cleanup <- mt7925_pci_remove

That was on MT7927. The USB parts tear down a different way and never
arrive, which is probably why this is easy to miss.

Would putting the disable next to the IRQ and tasklet work in your 2/2
cover mt7996? That keeps it where the driver already knows whether it
has stopped RX.

Devin