[dpdk-dev] [PATCH v2] net/i40e: fix wrong handle when enable interrupt

[Wu, Jingjing]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Zhang, Qi Z
> Sent: Tuesday, March 21, 2017 7:34 PM
> To: Thomas Monjalon <thomas.monjalon at 6wind.com>
> Cc: dev at dpdk.org; Yigit, Ferruh <ferruh.yigit at intel.com>
> Subject: Re: [dpdk-dev] [PATCH v2] net/i40e: fix wrong handle when enable
> interrupt
> 
> Hi Thomas:
> 
> 
> > -----Original Message-----
> > From: Zhang, Qi Z
> > Sent: Tuesday, March 21, 2017 8:10 PM
> > To: Wu, Jingjing <jingjing.wu at intel.com>; Zhang, Helin
> > <helin.zhang at intel.com>
> > Cc: dev at dpdk.org; Zhang, Qi Z <qi.z.zhang at intel.com>; stable at dpdk.org
> > Subject: [PATCH v2] net/i40e: fix wrong handle when enable interrupt
> >
> > In i40e_dev_interrupt_handler, when call rte_intr_enable, the
> > intr_handle is the copy when we registered.
> > According to interrupt handle framework, if the requirement of
> > intr_handle is changed, we need to unregister then register a new
> > copy. This happens on i40e driver when bind to vfio-pci, the
> > rte_intr_efd_enable function will modify the max_intr according the
> > queue number, so a new copy of intr_handle need to be registered.
> > Without this fix, we saw lw3fwd-power does not work due to wrong
> > interrupt count in vfio_irq_set when set vfio interrupt.
> >
> > Fixes: 2ce7a1ed09fc ("net/i40e: localize mapping of ethdev to PCI
> > device")
> >
> > Cc: stable at dpdk.org
> >
> > Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> > ---
> > v2:
> > - follow current design, when intr_handle is modified, unregister
> >   the old one and register the new one.
> > - there should be a patch set to fix on other devices.
> >
> >  drivers/net/i40e/i40e_ethdev.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/net/i40e/i40e_ethdev.c
> > b/drivers/net/i40e/i40e_ethdev.c index 9c76baa..e7bbea5 100644
> > --- a/drivers/net/i40e/i40e_ethdev.c
> > +++ b/drivers/net/i40e/i40e_ethdev.c
> > @@ -1886,6 +1886,14 @@ i40e_dev_start(struct rte_eth_dev *dev)
> >  		ret = rte_intr_efd_enable(intr_handle, intr_vector);
> >  		if (ret)
> >  			return ret;
> > +		 /**
> > +		  * intr_handle may be modified in rte_intr_efd_enable
> > +		  * so unregster the old one and register the new one.
> > +		  */
> > +		rte_intr_callback_unregister(intr_handle,
> > +			i40e_dev_interrupt_handler, dev);
> > +		rte_intr_callback_register(intr_handle,
> > +			i40e_dev_interrupt_handler, dev);
> To me, this fix looks a little bit weird.
> May I know why we need to register an copy of intr_handle ?
> What do you think about my previous clean up patch.
> http://dpdk.org/dev/patchwork/patch/21529/
> Thanks
> Qi.

It seems [dpdk-dev,v2,1/3] vfio: keep interrupt source read only
http://www.dpdk.org/dev/patchwork/patch/21528/ is already
be acked by Anatoly.

I think we need to support that change, but not this workaround.