Re: consequences of setting net_device_ops ndo_change_carrier()?

["Robert P. J. Day" <rpjday@crashcourse.ca>]

On Sat, 4 Aug 2018, Stephen Hemminger wrote:

... big snip ...

> ndo_change_carrier is not the droid your looking for.
>
> The purpose of ndo_change_carrier was for testing network devices
> (ie dummy), and also for cases like network tunnels where the
> sofrware carrier state may be controlled by a userspace daemon.
>
> Real network devices call netif_carrier_on and netif_carrier_off
> when they notice change in carrier state in hardware. Typically,
> this is when an interrupt happens.

  i had actually come to just that conclusion, as i was digging
through the code, and couldn't immediately see why setting
ndo_change_carrier() would cause a problem. in fact, to help my
admittedly painful newbie-level debugging, i started a wiki page to
track this (i document *everything* on wiki pages):

  http://crashcourse.ca/dokuwiki/doku.php?id=ndo_change_carrier

so i am reduced to concluding that the drivers in question are simply
not calling correctly the very routines you mention.

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                  http://crashcourse.ca/dokuwiki

Twitter:                                       http://twitter.com/rpjday
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