Re: infinite spin in RT when booting with DHCP on

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello Tim,

On Thu, Feb 02, 2012 at 01:38:44PM +0100, Tim Sander wrote:
> Hi
> > When booting my platform with DHCP on, the DHCP request is sent by the
> > network driver before the PHY has even started the autonegotiation.
> > Since the PHY is not ready, the TX interrupt returns with NETDEV_TX_BUSY
> > but the softirq [sirq-net-tx] seems to have entered an infinite spin, as
> > my system is practically hung and 'top' reveals [sirq-net-tx/0] is
> > consuming 95% of CPU. This is preventing the PHY autonegotiation (which is
> > scheduled as a delayed work) to start, so the PHY is never ready and the
> > packet never reaches the network.
> Mh, i think i am hit by the same problem. I have a i.mx 35 and when dhcp is
> enabled the ksoftirq is also running wild with 3.0-rt. This also happens when
I fail to reproduce that on a pcm043 machine using 3.0.18-rt34. Can you
provide me your config. Does the problem occur on every boot for you? If
not, how often do I need to reboot?

@Hector: Greeting to Spain. I don't have an imx51 machine handy, but
your config and your answers on my questions might help, too.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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