On Fri, 2014-03-14 at 17:51 -0400, David Miller wrote: > From: "Tantilov, Emil S" <emil.s.tantilov@xxxxxxxxx> > Date: Fri, 14 Mar 2014 20:19:38 +0000 > > > That would work, but what if there are other callers of > > ndo_start_xmit that don't have this check? Handling this in the > > driver takes care of all instances. > > netif_carrier_off() is supposed to stop traffic from flowing to > the device. > > The qdisc layer should be honoring this property, and my > suspicion is that it is just netpoll operates in the unique > environment that doesn't. There is no check for netif_carrier_ok() in the qdisc transmit path. Instead netif_carrier_off() eventually causes link_watch to call dev_deactivate() which installs the noop qdisc. It does seem like transmitters that bypass the qdisc should be checking netif_carrier_ok(), but drivers must also accept that the effect of netif_carrier_off() is not immediate. Maybe ixgbe is not calling netif_stop_all_queues() at quite the right time? Ben. -- Ben Hutchings When you say `I wrote a program that crashed Windows', people just stare ... and say `Hey, I got those with the system, *for free*'. - Linus Torvalds
Attachment:
signature.asc
Description: This is a digitally signed message part