[mythtv-users] Hauppauge 2250 causes dropped network packets

[John Kasunich]

On Sun, 28 Mar 2010 21:23 -0400, "Robert Shields" <rwshields at gmail.com>
wrote:

> On Sun, Mar 28, 2010 at 6:57 PM, John Kasunich
> <jmkasunich at fastmail.fm>wrote:
> 
> > Built this PC a couple months ago.
> >
> > Motherboard is Asus M4A77D
> > Network is the onboard NIC:
> > 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd.
> > RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
> >
> > Networking works fine when the Hauppauge 2250 PCI Express tuner
> > card is not in the machine.
> >
> > When I installed the tuner card, I started getting 5-15% dropped
> > packets.  The packets are being dropped in the very first hop,
> > from the PC to my DSL router/modem.  Other PCs on the same network
> > never drop packets, and removing the tuner card makes this PC start
> > working fine again.

> I have two 220s in my system and haven't noticed this (I have had no
> visible
> LAN issues, so I never had a reason to go looking to deep though).
> 
> A good first step is to simply try the card(s) in different
> slots...sometimes you get lucky and this clears up the possible
> conflicts.

I have two x1 PCIe slots, tried both, no difference.

> If the problem persists, maybe look in your BIOS for a way of setting the
> different interrupts or something along those lines.

I suspected interrupt issues, but the NIC and the tuner card are both
assigned separate interrupts according to lspci.  
 
> I am not a huge linux know-it-all so I am not sure where to begin in the
> actual OS.

Unfortunately I'm not that familiar with PCI troubleshooting either.
The results of lspci -vvv and the contents of /proc/interrupts with and
without the tuner installed are here:
http://paste.ubuntu.com/405203/

The main difference is that the tuner adds another PCI bridge, and
NIC moves from bus 02:00.0 with IRQ27, to bus 03:00.0 and IRQ 28.
The tuner card uses IRQ 11.

The lost packets are definitely happening in the very first hop.  The
test I've been running is:

sudo ping -f -w10 192.168.1.254

which pings my router (192.168.1.254) as fast as it can for 10 seconds.
With the tuner out, it does 8000 to 11000 packets, with no lost packets.
With the tuner installed, it does about half that many, with 5 to 15%
packet loss.

The OS is Ubuntu 9.10, kernel is 2.6.31-20-generic #58-Ubuntu SMP x86_64

Can anybody suggest any other tests?

John Kasunich


-- 
  John Kasunich
  jmkasunich at fastmail.fm