Re: followup: what's responsible for setting netdev->operstate to IF_OPER_DOWN?
On Sun, 26 Aug 2018, Stephen Hemminger wrote:
> On Sun, 26 Aug 2018 11:14:33 -0400 (EDT)
> "Robert P. J. Day" wrote:
>
> > apologies for the constant pleas for assistance, but i think i'm
> > zeroing in on the problem that started all this. recap: custom
> > FPGA-based linux box with multiple ports, where the current symptom is
> > that there is no userspace notification when someone simply unplugs
> > one of the ports ("ifconfig" shows that interface still RUNNING).
> >
> > as i read it, an active ethernet interface should be both UP (the
> > administrative state) and RUNNING (the RFC 2863-defined operational
> > state). if i unplug, i've verified on a standard net port on my laptop
> > that the interface is still UP, but no longer RUNNING, which makes
> > perfect sense. i plug back in, interface starts RUNNING again. so
> > where's the problem?
> >
> > i can see that whether ifconfig shows an interface RUNNING is
> > defined in net/core/dev.c:
> >
> > unsigned int dev_get_flags(const struct net_device *dev)
> > {
> > unsigned int flags;
> >
> > flags = (dev->flags & ~(IFF_PROMISC |
> > IFF_ALLMULTI |
> > IFF_RUNNING |
> > IFF_LOWER_UP |
> > IFF_DORMANT)) |
> > (dev->gflags & (IFF_PROMISC |
> > IFF_ALLMULTI));
> >
> > if (netif_running(dev)) {
> > if (netif_oper_up(dev))
> > flags |= IFF_RUNNING; < THERE
> > if (netif_carrier_ok(dev))
> > flags |= IFF_LOWER_UP;
> > if (netif_dormant(dev))
> > flags |= IFF_DORMANT;
> > }
> >
> > return flags;
> > }
> >
> > where netif_oper_up() is defined as:
> >
> > static inline bool netif_oper_up(const struct net_device *dev)
> > {
> > return (dev->operstate == IF_OPER_UP ||
> > dev->operstate == IF_OPER_UNKNOWN /* backward compat */);
> > }
> >
> > so i am simply assuming that the underlying problem is that,
> > somewhere down below, the unplugging of a port is somehow not setting
> > dev->operstate to its proper value of IF_OPER_DOWN.
> >
> > that would clearly explain everything, and i'm about to dig even
> > further to see where the event of unplugging a port *should* be
> > recognized, but does this sound like a reasonable diagnosis? there
> > have been other problems with the programming of the FPGA, so it would
> > surprise absolutely no one to learn that this aspect was
> > misprogrammed.
> >
> > rday
> >
>
> There is no reason drivers should ever muck with flags directly.
> You probably are looking for netif_detach
i assume you mean netif_device_detach; i'll check into that.
rday
--
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca/dokuwiki
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
Re: followup: what's responsible for setting netdev->operstate to IF_OPER_DOWN?
On Sun, 26 Aug 2018 11:14:33 -0400 (EDT)
"Robert P. J. Day" wrote:
> apologies for the constant pleas for assistance, but i think i'm
> zeroing in on the problem that started all this. recap: custom
> FPGA-based linux box with multiple ports, where the current symptom is
> that there is no userspace notification when someone simply unplugs
> one of the ports ("ifconfig" shows that interface still RUNNING).
>
> as i read it, an active ethernet interface should be both UP (the
> administrative state) and RUNNING (the RFC 2863-defined operational
> state). if i unplug, i've verified on a standard net port on my laptop
> that the interface is still UP, but no longer RUNNING, which makes
> perfect sense. i plug back in, interface starts RUNNING again. so
> where's the problem?
>
> i can see that whether ifconfig shows an interface RUNNING is
> defined in net/core/dev.c:
>
> unsigned int dev_get_flags(const struct net_device *dev)
> {
> unsigned int flags;
>
> flags = (dev->flags & ~(IFF_PROMISC |
> IFF_ALLMULTI |
> IFF_RUNNING |
> IFF_LOWER_UP |
> IFF_DORMANT)) |
> (dev->gflags & (IFF_PROMISC |
> IFF_ALLMULTI));
>
> if (netif_running(dev)) {
> if (netif_oper_up(dev))
> flags |= IFF_RUNNING; < THERE
> if (netif_carrier_ok(dev))
> flags |= IFF_LOWER_UP;
> if (netif_dormant(dev))
> flags |= IFF_DORMANT;
> }
>
> return flags;
> }
>
> where netif_oper_up() is defined as:
>
> static inline bool netif_oper_up(const struct net_device *dev)
> {
> return (dev->operstate == IF_OPER_UP ||
> dev->operstate == IF_OPER_UNKNOWN /* backward compat */);
> }
>
> so i am simply assuming that the underlying problem is that,
> somewhere down below, the unplugging of a port is somehow not setting
> dev->operstate to its proper value of IF_OPER_DOWN.
>
> that would clearly explain everything, and i'm about to dig even
> further to see where the event of unplugging a port *should* be
> recognized, but does this sound like a reasonable diagnosis? there
> have been other problems with the programming of the FPGA, so it would
> surprise absolutely no one to learn that this aspect was
> misprogrammed.
>
> rday
>
There is no reason drivers should ever muck with flags directly.
You probably are looking for netif_detach
Re: followup: what's responsible for setting netdev->operstate to IF_OPER_DOWN?
On Sun, 26 Aug 2018, Andrew Lunn wrote:
> On Sun, Aug 26, 2018 at 11:14:33AM -0400, Robert P. J. Day wrote:
> >
> > apologies for the constant pleas for assistance, but i think i'm
> > zeroing in on the problem that started all this. recap: custom
> > FPGA-based linux box with multiple ports, where the current
> > symptom is that there is no userspace notification when someone
> > simply unplugs one of the ports ("ifconfig" shows that interface
> > still RUNNING).
>
> What are you using for a PHY? Are you using phylib or phylink? I
> strongly suggest you do, and then you don't need to care about any
> of this.
i'm not sure i'm even allowed to talk about that given the NDA --
i'll just muddle through following the code until i figure out what is
failing to notify userspace. le *sigh*.
rday
--
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca/dokuwiki
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
Re: followup: what's responsible for setting netdev->operstate to IF_OPER_DOWN?
On Sun, Aug 26, 2018 at 11:14:33AM -0400, Robert P. J. Day wrote:
>
> apologies for the constant pleas for assistance, but i think i'm
> zeroing in on the problem that started all this. recap: custom
> FPGA-based linux box with multiple ports, where the current symptom is
> that there is no userspace notification when someone simply unplugs
> one of the ports ("ifconfig" shows that interface still RUNNING).
What are you using for a PHY? Are you using phylib or phylink? I
strongly suggest you do, and then you don't need to care about any of
this.
Andrew
