It's probably a good idea to look at the content of the file "/proc/interrupts" it see which devices are sharing IRQs. Here is what mine looks like:


Some devices do OK sharing IRQs; others do not. My understanding is that the Hauppauge cards (listed as ivtv) and nvidia graphics cards do not like to share IRQs. In my case I am not using my USB ports for anything, so that fact that the nvidia card is sharing an IRQ with some of my USB ports doesn't matter.

If you find that your happauge card is sharing IRQs some things you can do are:

1. Disable unused serial ports, parallel ports and USB ports in your BIOS. This will free up some IRQs.

2. Moving a card to a different PCI slot will change the IRQ it is using.

Marc

Ok, here is what my file looks like. I'm not using my USB ports etiher.. I'm not entirely sure what to make of this file. I don't know what a lot of the devices are. Can you help?

Let me start by saying that I cannot be certain that your problems are caused by IRQ sharing. Having said this, I believe that having your graphics card share an IRQ with your firewire card is not good. I also see that the Hauppauge card is sharing an IRQ with what looks like your SATA controller (am I correct that you are using at least one SATA drive?)

My suggestion is that you do the following:

1. Remove all PCI cards that aren't absolutely required to run your system. If you have a card that you would "like to have", but can live without for now, pull it.

2. Your MOBO probably has a lot of built-in devices. Disable everything you don't absolately need in your BIOS. ie: All USB ports, serial port, parallel ports, firewire (1394) if its built into the mobo, etc. If you don't need it, turn it off.

3. I would also pull out one of your tuner cards.

If your system is stable like this, you can start adding things back in 1 at a time. Add in the stuff that's most important to you first. This way, you will be able to determine exactly which device is causing the problem.

If you decide to do this, post the contents of /proc/interrupts after you've taken all 3 steps -- I'd like to see what things look like at that point.

Marc

I went into my BIOS and disabled all the serial, parallel and other ports I wasn't using. Below is the new configuration.

So, if I'm right, it means that my SATA drive is still sharing an IRQ with my ivtv0. Is there a way that I can move that? I don't have any extra PCI cards. The only PCI cards I have are two tuners and my Video card.

My BIOS has a setting for "Plug and Play OS". That's currently set to No, should I change that to Yes?

Looks like progress -- your nvidia card is on it's own IRQ now. I'm don't recall what my "plug and play OS" setting is set to and my wife is watching a show so I can't reboot right now. I would leave this as currently set for now. At this point, I see 3 choices:

1. Run as you are for now and see if things are stable.

2. Remove one of the two tuner cards and then run for a while to see if you are stable.

3. Moving a PCI card to a different slot will change the IRQ it uses. If you look at your mobo manual it might even show you which PCI slot is assigned which IRQ. I am guessing you have 4 or 5 PCI slots, with 2-3 of them empty. You can try moving one of the tuners to one of the empty PCI slots and see if that gets it to it's own IRQ.

Marc

whitlmr, just curious as to how things are going.

Marc

Things were stable for a couple of days, but I'm getting lockups again. I think that I need to get in there and move around some PCI cards to get them off critical shared interrupts. I'm hoping to have some time to do that tonight. I think before I do that though, I may turn on the "plug and play OS" option in the BIOS. I'm wondering if that will allow Linux to dynamically set the interrupts... I'm not sure it's smart enough for that, but I think it's worth a try before I lug the thing out from under my tv and open the case.

Thanks for checking!

I have been having similar weirdness since R5D1. System spec in sig. I get lots of DMA errors from my pvr-150 card, occasional lockups, x lockups, backend dying, backend not starting, etc. My hardware is solid.
Check /var/log/messages and see if you have any DMA error messaged with ivtv, also /var/log/mythtv/mythbackend.log would be a good place to look for clues. Good luck, I think it's related to IVTV and the DMA errors but haven't found a fix yet...

Plug and Play OS should be Yes AFAIK. I've played with my BIOS settings endlessly and no luck in my case.

_________________
MythTV box: Opty 170, MSI K8NGM2-FID, 1.5 GB PC2700, Seagate 7200.10 400GB, Lite-On Combo drive. PVR-150, HDHomeRun. Antec Sonata, Freezer 64 Pro. Oh so quiet.

Thanks for the log tips modemboy.

The Plug and Play OS option didn't seem to make a different, I still am getting lockups. I'm going to try moving cards and looking at the log stuff as soon as I get a few free minutes.

Whitlmr, I suggest you start by removing one of the tuner cards, make sure the remaining tuner card is on it's own IRQ and then run as a 1-tuner config. If that works, you can then add back the second tuner card and play with IRQ assignments in a 2-card config. If it won't work as a single-tuner config and that tuner on a dedicated IRQ, then the problem is likely elsewhere.

Marc

I have a combined frontend/backend Mythbox. I had random lockups, too, where playbacks would freeze and repeat the last 1/4 second of audio continuously until I rebooted. I noticed some kernel error messages related to APIC. Once I disabled APIC in the BIOS, the lockups stopped. Well, mostly. Now it's something else in the frontend (the backend happily keeps recording). No more reboots, though.

To make recovery easy, I (a) mark the current playback location (with spacebar) occasionally; and (b) have a bash (shell) window open, so I can kill the frontend or restart the backend (if things really get hosed) without leaving my chair (hint: wireless keyboard).

To get a bash shell, do it outside the frontend, or just before the frontend comes up.

If Frontend is running:
- exit the frontend (use ESC), open the bash window (right-click, menu Apps, Shells, Bash), and re-run MythTV (menu Apps, Graphics, MythTV).

While Booting:
- When the splash screen with the couch-penguin watching KnoppMyth comes up, quickly hit the right mouse button--an X menu (maybe fluxbox?) will appear.
- The keyboard is disabled briefly at this point.
- Use the mouse to select menu Apps, Shells, Bash.
- Alt-TAB returns you to the frontend.

Here's a handy frontend-killer script (it echoes the process info before killing):
And a partial run:

Now if the frontend hangs, I just alt-TAB, type ./killf TAB ENTER, and frontend goes away. Definitely a workaround, but hey, no rebooting.

I finally got around to cracking the case. I only have two PCI slots (and two tuners) so I really can't move things. I found this page http://www.ibm.com/developerworks/library/l-hw2.html on IRQ conflicts in linux. I turned the Plug and Play OS OFF, set the configuration of PCI slots to manual and assigned every IRQ I could to "PCI SLOT" not reserved (for legacy devices.

I also took out the BTTV card, so I just have PVR-150 in the system.

Before my IRQ's looked like this



Now they look like this



I'm going to run it for a few days and see how things shake out. I guess I may end up trying to get a PVR-350 or whatever card has dual tuners if my bttv card turns out to be the problem.

All weekend and today (Monday) without any lockups.. Seems like it was an IRQ problem. So what's my best bet to get dual tuners a PVR-350?

Another experiment I would try first is to try the BTTV card by itself. The goal is to determine if that card is stable. If that works, I would then re-install both cards, but in the opposite slots they were in originally. It's a long shot, but perhaps worth a try...


Marc

Another thought -- I notice that your system doesn't use IRQs 2 & 4 at all. Did you try the "Reset ESCD data" outlined in the article your referenced?

Marc