On 4/14/21 10:08 AM, Lijun Pan wrote:
> There are chances that napi_disable can be called twice by NIC driver.
> This could generate deadlock. For example,
> the first napi_disable will spin until NAPI_STATE_SCHED is cleared
> by napi_complete_done, then set it again.
> When napi_disable is called the second time, it will loop infinitely
> because no dev->poll will be running to clear NAPI_STATE_SCHED.
>
> Though it is driver writer's responsibility to make sure it being
> called only once, making napi_disable more robust does not hurt, not
> to say it can prevent a buggy driver from crashing a system.
This is hard to digest. A buggy driver has plenty of ways to crash the system.
If you need help to fix the buggy driver, please ask for help.
