Date: Sat, 13 Sep 2014 13:09:14 -0700 From: Eric Joyner <ricera10@gmail.com> To: Adrian Chadd <adrian@freebsd.org> Cc: Jack F Vogel <jfv@freebsd.org>, FreeBSD Net <freebsd-net@freebsd.org>, "Joyner, Eric" <eric.joyner@intel.com> Subject: Re: [igb] add DROP_EN to each RX queue config if TX flow control is disabled Message-ID: <CA%2Bb0zg_Eq7wLP6SRCpBUT5DXDPSxSk=WFZ7-c98W_Xg74-Krzg@mail.gmail.com> In-Reply-To: <CAJ-Vmok6aSE=ZFZcrBCZUTdHTXosE2eAzG%2Bxkhwn=XM7c7P3Pg@mail.gmail.com> References: <CAJ-Vmok6aSE=ZFZcrBCZUTdHTXosE2eAzG%2Bxkhwn=XM7c7P3Pg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
This looks good to me. The only comment I have is that according to the I350 datasheet, DROP_EN is already set on all the queues but 0 by default, but I haven't checked for the other adapters covered by igb. --- - Eric Joyner On Mon, Sep 8, 2014 at 10:12 PM, Adrian Chadd <adrian@freebsd.org> wrote: > Hi, > > This patch enables the DROP_EN flag to each RX queue if TX flow > control is disabled. It (mostly) mirrors what the ixgbe driver does. > > This prevents a single full RX ring from stalling the rest of the RX rings. > > How's it look? (indenting and such aside, thanks google.) > > > > -a > > Index: sys/dev/e1000/if_igb.c > =================================================================== > --- sys/dev/e1000/if_igb.c (revision 271290) > +++ sys/dev/e1000/if_igb.c (working copy) > @@ -4712,6 +4712,18 @@ > rctl |= E1000_RCTL_SZ_2048; > } > > + /* > + * If TX flow control is disabled and there's >1 queue defined, > + * enable DROP. > + * > + * This drops frames rather than hanging the RX MAC for all queues. > + */ > + if ((adapter->num_queues > 1) && > + (adapter->fc == e1000_fc_none || > + adapter->fc == e1000_fc_rx_pause)) { > + srrctl |= E1000_SRRCTL_DROP_EN; > + } > + > /* Setup the Base and Length of the Rx Descriptor Rings */ > for (int i = 0; i < adapter->num_queues; i++, rxr++) { > u64 bus_addr = rxr->rxdma.dma_paddr; > @@ -6255,6 +6267,7 @@ > > adapter->hw.fc.current_mode = adapter->hw.fc.requested_mode; > e1000_force_mac_fc(&adapter->hw); > + /* XXX TODO: update DROP_EN on each RX queue if appropriate */ > return (error); > } > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2Bb0zg_Eq7wLP6SRCpBUT5DXDPSxSk=WFZ7-c98W_Xg74-Krzg>