[dpdk-dev] [PATCH v2] ixgbe: Fix disable interrupt twice

[Lu, Wenzhuo]

Hi Michael,

> -----Original Message-----
> From: Qiu, Michael
> Sent: Monday, February 1, 2016 4:05 PM
> To: Lu, Wenzhuo; dev at dpdk.org
> Cc: Zhou, Danny; Liu, Yong; Liang, Cunming
> Subject: Re: [PATCH v2] ixgbe: Fix disable interrupt twice
> 
> On 1/29/2016 4:07 PM, Lu, Wenzhuo wrote:
> > Hi Michael,
> >
> >> -----Original Message-----
> >> From: Qiu, Michael
> >> Sent: Friday, January 29, 2016 1:58 PM
> >> To: dev at dpdk.org
> >> Cc: Zhou, Danny; Liu, Yong; Liang, Cunming; Lu, Wenzhuo; Qiu, Michael
> >> Subject: [PATCH v2] ixgbe: Fix disable interrupt twice
> >>
> >> Currently, ixgbe vf and pf will disable interrupt twice in stop stage
> >> and uninit stage. It will cause an error:
> >>
> >>     testpmd> quit
> >>
> >>     Shutting down port 0...
> >>     Stopping ports...
> >>     Done
> >>     Closing ports...
> >>     EAL: Error disabling MSI-X interrupts for fd 26
> >>     Done
> >>
> >> Becasue the interrupt already been disabled in stop stage.
> >> Since it is enabled in init stage, better remove from stop stage.
> > I'm afraid it's not a good idea to just remove the intr_disable from dev_stop.
> > I think dev_stop have the chance to be used independently with dev_unint. In
> this scenario, we still need intr_disable, right?
> > Maybe what we need is some check before we disable the intr:)
> 
> Yes, indeed we need some check in disable intr, but it need additional fields in
> "struct rte_intr_handle",  and it's much saft to do so, but as I check i40e/fm10k
> code, only ixgbe disable it in dev_stop().
I found fm10k doesn't enable intr in dev_start. So, I think it's OK. But i40e enables intr in dev_start.
To my opinion, it's more like i40e misses the intr_disable in dev_stop.
Maybe we can follow fm10k's style.

> 
> On other hand, if we remove it in dev_stop, any side effect? In ixgbe start, it will
> always disable it first and then re-enable it, so it's safe.
I think you mean we can disable intr anyway even if it has been disabled. Sounds more like why we don't
need this patch :)

> 
> Thanks,
> Michael
> >