Re: [PATCH v1 1/3] net: hisilicon: make hip04_tx_reclaim non-reentrant

[Jakub Kicinski]

On Sat, 3 Aug 2019 20:31:39 +0800, Jiangfeng Xiao wrote:
> If hip04_tx_reclaim is interrupted while it is running
> and then __napi_schedule continues to execute
> hip04_rx_poll->hip04_tx_reclaim, reentrancy occurs
> and oops is generated. So you need to mask the interrupt
> during the hip04_tx_reclaim run.

Napi poll method for the same napi instance can't be run concurrently.
Could you explain a little more what happens here?

Also looking at hip04_rx_poll() I don't think the interrupt re-enabling
logic guarantees the interrupt is not armed when NAPI is scheduled.
Please note that NAPI is no longer scheduled if napi_complete_done()
returned false.