> -----Original Message-----
> From: Michael Chan [mailto:michael.c...@broadcom.com]
> Sent: Thursday, December 14, 2017 2:16 AM
> To: Chopra, Manish <manish.cho...@cavium.com>
> Cc: da...@davemloft.net; netdev@vger.kernel.org;
> andrew.gospoda...@broadcom.com; Elior, Ariel <ariel.el...@cavium.com>;
> Dept-Eng Everest Linux L2 <dept-engeverestlinu...@cavium.com>
> Subject: Re: [PATCH net-next v4 4/5] bnx2x: Use NETIF_F_GRO_HW.
>
> On Wed, Dec 13, 2017 at 1:08 AM, Chopra, Manish
> <manish.cho...@cavium.com> wrote:
> >
> > Hi Michael, There seems a behavioral change here. This driver support
> > two HW aggregation modes [LRO and GRO] With the changes, Interfaces
> come with HW GRO enabled and LRO disabled by default as opposed to earlier
> where interfaces used to come with LRO enabled.
>
> Right. Before, you had both NETIF_F_GRO and NETIF_F_LRO set and the code
> looked at NETIF_F_LRO first and turned on LRO.
>
> Now, we set NETIF_F_GRO and NETIF_F_GRO_HW by default. NETIF_F_LRO is
> turned off since NETIF_F_GRO_HW is on.
>
> If you want, I can change it back to the old default.
Yes please, I think we should not make any default behavior change.
Few more comments -
1). This driver uses module param "disable_tpa" also to completely disable TPA
[whether it be LRO or HW GRO] along the initialization flow.
For ex.
/*Set TPA flags*/
if (bp->disable_tpa) {
bp->dev->hw_features &= ~NETIF_F_LRO;
bp->dev->features &= ~NETIF_F_LRO;
}
I think we should also disable HW gro here as well, so that device will come up
with no TPA at all.
2). In bnx2x_fix_features() we used to do before these changes -
/* TPA requires Rx CSUM offloading */
if (!(features & NETIF_F_RXCSUM)) {
features &= ~NETIF_F_LRO;
features &= ~NETIF_F_GRO;
}
I think we should not turn off SW gro here, we should turn off HW gro here now ?
>
> >
> > Also, there seems some problem when turning on LRO even after GRO disable.
> > When I tried to disable GRO and then tried to enable LRO it didn't go well.
> > Not
> sure why ?
>
> I just put an old BCM57810 card into my machine and it works for me.
> As long as I turn off GRO or GRO_HW, I can turn on LRO.
>
> [root@localhost bnx2x]# ethtool -K p1p1 lro on Cannot get device udp-
> fragmentation-offload settings: Operation not supported Cannot get device
> udp-fragmentation-offload settings: Operation not supported Could not change
> any device features [root@localhost bnx2x]# ethtool -K p1p1 gro off Cannot get
> device udp-fragmentation-offload settings: Operation not supported Cannot get
> device udp-fragmentation-offload settings: Operation not supported Actual
> changes:
> generic-receive-offload: off
> large-receive-offload: on
> rx-gro-hw: off [requested on]
> [root@localhost bnx2x]# ethtool -K p1p1 lro on Cannot get device udp-
> fragmentation-offload settings: Operation not supported Cannot get device
> udp-fragmentation-offload settings: Operation not supported
Doesn't sound like HW specific.
Probably, I was testing on your older series, I will check again on latest
series.
