Issue with sched-no-work-when-pi-blocked.patch

Issue with sched-no-work-when-pi-blocked.patch

[Daniel Glöckner]

Hi,

on a system running 3.2.23-rt37 the boot time is increased by two
minutes because of commit 4b03ee27 (sched-no-work-when-pi-blocked.patch)
when booting with ip=dhcp. This is due to ic_open_devs taking rtnl_mutex
before it ups the network interfaces. The ndo_open function then calls
netif_carrier_off which queues a work that as well takes rtnl_mutex. This
stalls the workqueue (tsk_is_pi_blocked()) and prevents phy_state_machine
and thus netif_carrier_on from being run. ic_open_devs waits for two minutes
for a link before it gives up and releases rtnl_mutex.

So, what is the rationale behind sched-no-work-when-pi-blocked.patch?

On the other hand, I think I'll just drop rtnl_mutex in ic_open_devs
while it is waiting for a link.

  Daniel

-- 
Dipl.-Math. Daniel Glöckner, emlix GmbH, http://www.emlix.com
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