Rett D. Walters wrote: > Hans Verkuil wrote: > >> There is nothing I can do about it. DMA issues have always plagued the >> cx23415/16 based cards. The cause is the buggy DMA engine of these >> cards and that is not something I can do anything about. Depending on >> your system, chipset and the phase of the moon you may or may not be >> hit by these DMA problems. In general using RAID for your harddisks is >> not recommended, also using a video card that uses normal RAM for its >> video memory is a problem. After that your best bet is to replace your >> motherboard. Intel chipsets seem to work best, at least I have seen few >> if any issues with them. But many people also have no problems with ATI >> and nVidia chipsets (including myself), so it does not seem to >> be 'just' the chipset, but a combination of factors. >> >> Note that the PVR500 seems to be less susceptible to these problems as >> well: the DMA bridge on that card seems to isolate the cx23416 chips >> from the DMA issues. >> >> Note that these problems also occur under Windows, I know that Hauppauge >> have modified their Windows driver to be able to very quickly reset the >> DMA engine when they detect problems. Apparently this is very >> complicated code and (not surprisingly) they won't release details on >> it. I can't blame them for that, I'd probably do the same in their >> position. Otherwise Hauppauge has been very supportive to me and linux >> in general. >> >> >> > Ok - I understand the issue. Knowing that the problems occur under > windows as well is good to know. It seemed strange to me that the > windows driver worked fine and the Linux one has issues, however we have > no way of knowing whats really happening under the hood without your > information from Hauppauge. I was a bit confused that I had never had a > problem like this before (I have 3 250's) in 3 different machines and > never ran into the issue until I upgraded a motherboard in one of them. > We use the Asus M2NPV-VM motherboards in myPVR 2.0 and they work really well with the 0.4.x drivers since we worked through some of the DMA issues with Hans. I've also tested these boards with recent Ubuntu Feisty and Mythbuntu builds which use much more recent drivers.
If you are running MythTV one tip is to enable "Delete files slowly" as it prevents some I/O overloading issues that can cause DMA problems, but in general I don't have issues with the PVR 150 and PVR 500 cards we use. Steve _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
