The issue that Mario is referring to is a tricky one.  What we've found
is related to the receive path.  We get an interrupt from the card
saying that a packet has been received and, in our interrupt handler, we
go through and check to see if any receive descriptors are available for
processing and then process them.  It appears that we quite frequently
end up with the scenario where the Rx interrupt goes off BUT none of the
descriptors are marked as ready to be processed, so, of course, we don't
do anything.  It appears that shortly after this, the descriptor s get
updated as ready for processing but, of course, it's already too late
since we've checked and not found any that are ready.  This means that
we often end up with the situation in which packets are left in the
receive queue , potentially for long periods of time (depending upon the
network traffic patterns).

	We're still trying to figure out what to do about this.  We
don't know if it's something fundamental to the way that PCI Express
works or if it's a card configuration issue.  We're investigating :>

I'll have to post this in the networking forum as well come to think of
it...

	Robert.

-----Original Message-----
From: Mario Charest [mailto:community-noreply@qnx.com] 
Sent: Tuesday, November 11, 2008 9:55 AM
To: momentics-community
Subject: RE: PCI Express - any special support needed?

Nothing special is needed, but be aware that there are problem with some
model of PCI Express network card ( Intel ) QNX is working on the issue.

-----Original Message-----
From: Steve Huggins [mailto:community-noreply@qnx.com]
Sent: November-11-08 9:23 AM
To: momentics-community
Subject: PCI Express - any special support needed?

Our hardware engineers want to use an x86 based system with a PCI
Express slot. Do I need anything special from QNX to access PCI Express
devices as compared to accessing PCI devices (pci-bios)? We're currently
using Momentics 6.2.1B. Thanks.

Steve Huggins

_______________________________________________
QNX Momentics Community Support
http://community.qnx.com/sf/go/post16380



_______________________________________________
QNX Momentics Community Support
http://community.qnx.com/sf/go/post16385