call for bge(4) testers
oleg at freebsd.org
Wed Aug 23 12:54:41 UTC 2006
On Wed, Aug 23, 2006 at 04:40:35PM +0400, Oleg Bulyzhin wrote:
> On Wed, Aug 23, 2006 at 09:55:54AM +0900, Pyun YongHyeon wrote:
> > On Wed, Aug 23, 2006 at 12:43:42AM +0400, Oleg Bulyzhin wrote:
> > > On Tue, Aug 22, 2006 at 02:44:34PM +0200, Michael Reifenberger wrote:
> > > > On Tue, 22 Aug 2006, Pyun YongHyeon wrote:
> > > > ...
> > > > >I'm not familiar with vge(4) and don't have hardwares supported by
> > > > >vge(4). Because vge(4) supports a kind of interrupt moderation, there
> > > > >is a possiblity to have the same issue seen on em(4).
> > > > >If you want my blind patch I can send a patch for you.
> > > > >
> > > > Yes, please!
> > > > I can test it (on RELENG_6 though).
> > >
> > > I have an idea why those timeouts can happen. Could you please test
> > > attached patch? It may help (or may not). Anyway would be fine
> > > to know results.
> > >
> > Since vge(4) uses MTX_RECURSE mutex and miibus(4) handler is
> > protected with the mutex I guess it wouldn't help much.
> > I guess it needs a seperate mutex to protect miibus(4) handler
> > and should remove the use of MTX_RECURSE.
> 1) _ifmedia_upd() & _ifmedia_sts() functions are not called from mii layer.
> 2) As i can see MII layer is not protected by anything, unless you
> specially acquire driver lock prior to calling mii_ function.
> Locking ifmedia callbacks should be done (though, it may not help
> with watchdogs timeout), otherwise we have race on accessing PHY registers.
> As i can see, random watchdog timeouts was reported for em, bge, vge, sk
> (and maybe others, those ones which i remember) drivers.
> All of them has unlocked _ifmedia_ functions.
> My idea was: perhaps, under certain condition, concurrent access to PHY could
> lead to hardware deadlock.
> > vge(4) also has a bug
> > if mbuf chain is too long(7 or higher) and defragmentation with
> > m_defrag(9) fails it would access an invalid mbuf chain.
> > All these requires lots of work and need a real hardware.
> > Oleg, if you have hardware, would you fix it?
> Unfortunately i don't have vge hardware.
> > --
> > Regards,
> > Pyun YongHyeon
Forgot one thing: i think we need no dedicated mutex for mii layer if we lock
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