Re: [dpdk-dev] [PATCH 3/3] net/i40e: fix inadvertent override of vector RX allowance

["Ergin, Mesut A" <mesut.a.ergin@intel.com>]

Hi Qi,

> -----Original Message-----
> From: Zhang, Qi Z
> Sent: Wednesday, May 22, 2019 5:42 AM
> To: Ergin, Mesut A <mesut.a.ergin@intel.com>; Xing, Beilei
> <beilei.xing@intel.com>
> Cc: dev@dpdk.org
> Subject: RE: [PATCH 3/3] net/i40e: fix inadvertent override of vector RX
> allowance
> 
> Hi Mesut:
> 
> > -----Original Message-----
> > From: Ergin, Mesut A
> > Sent: Thursday, May 16, 2019 12:28 PM
> > To: Xing, Beilei <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> > Cc: dev@dpdk.org; Ergin, Mesut A <mesut.a.ergin@intel.com>
> > Subject: [PATCH 3/3] net/i40e: fix inadvertent override of vector RX allowance
> >
> > When i40e_rx_vec_dev_conf_condition_check_default() determines whether
> > vector receive functions would be allowed during initialization phase, it should
> > honor previously recorded disallowance during configuration phase, and not
> > override simply because it is for the first queue.
> >
> > Signed-off-by: Mesut Ali Ergin <mesut.a.ergin@intel.com>
> > ---
> >  drivers/net/i40e/i40e_rxtx_vec_common.h | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/net/i40e/i40e_rxtx_vec_common.h
> > b/drivers/net/i40e/i40e_rxtx_vec_common.h
> > index 0e6ffa0..f30cab4 100644
> > --- a/drivers/net/i40e/i40e_rxtx_vec_common.h
> > +++ b/drivers/net/i40e/i40e_rxtx_vec_common.h
> > @@ -212,6 +212,10 @@
> > i40e_rx_vec_dev_conf_condition_check_default(struct rte_eth_dev *dev)
> >  	if (rxmode->offloads & DEV_RX_OFFLOAD_VLAN_EXTEND)
> >  		return -1;
> >
> > +	/* Should not override if vector was already disallowed */
> 
> It is possible a device be reconfigured between dev_stop/dev_start, vector
> mode may fit for the new configure, so the old rx_vec_allowd should be
> ignored,
> 

i40e_dev_configure would reset rx_vec_allowed already. Am I missing 
another reconfiguration path?

Mesut

> Regards
> Qi
> 
> > +	if (!ad->rx_vec_allowed)
> > +	return -1;
> > +
> >  	/**
> >  	 * Vector mode is allowed only when number of Rx queue
> >  	 * descriptor is power of 2.
> > --
> > 2.7.4