Steven A. Falco wrote:
  

I am building kernel 2.6.25.4 from DENX with Xenomai 2.4.4 for PPC440EPx
(sequoia development board).

The kernel tries to use DHCP to obtain network settings.  With IPIPE
disabled, this works perfectly.  However, when I enable IPIPE, the board
sends packets ok, but does not receive packets - I can see the DHCP with
a sniffer, but the development board does not receive them.

External interrupts are probably locked out by the pipeline engine; I've fixed a
similar issue in recent patches for other PICs. Which I-pipe patch release are
you using?

Also, in order to disable IPIPE, I had to patch
kernel/time/tick-common.c around line 168. It is missing an ifdef:

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 58bfacf..3a735b8 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -163,9 +163,11 @@ static void tick_setup_device(struct tick_device *td,

td->evtdev = newdev;

+#ifdef CONFIG_IPIPE
/* I-pipe: derive global tick IRQ from CPU 0 */
if (cpu == 0)
ipipe_update_tick_evtdev(newdev);
+#endif

/*
* When the device is not per cpu, pin the interrupt to the

Signed-off-by: Steve Falco <sfalco@domain.hid>

If anyone has suggestions as to why IPIPE is blocking received ethernet
packets, I'd appreciate it.

Steve