On Thursday 24 April 2008 04:17:59 James fowler wrote: > I have the following system config: > nforce 780i SLI Motherboard > PVR-250 card > Fedora 8 with all updates. > > I had a real struggle getting this card to work in a stable way. I > was wanting to get some other peoples thoughts on this. I have had > this card for a long time, just so you know. > > First I started out with Fedora 7 all updates applied. The card gave > me multiple errors including the dread DMA timeouts. The others were > when watching TV on it, I would get the buffer's full errors, and > application not reading fast enough, blah, blah, blah. Video play > back quality was not very good to say the least. > > Finally, upgrade to Fedora 8 which yum updates install kernel version > 2.6.24.4-64.fc8. One set of problems went away. The video play back > looked great no longer getting the buffer full errors. However, the > DMA timeouts remained, usually occurring fairly quickly within around > 10 mins or so. > > Went through all the how to's and troubleshooting, and finally > started playing with the pci latency settings. Through MUCH trail > and error I finally am using the following settings: > > In the bios I have the default set to 176 for the pci latency. > In my rc.local startup I am using the following setting: > /sbin/setpci -v -s 05:09.0 latency_timer=80 > > Obviously the default of 64 never worked here. And the bios default > was the standard 32. > > The only PCI card in the system is the PVR-250. And according to the > lspci output the only pci device listed with the latency of 176 is > the intergrated firewire adapter. All other intergrated devices I am > fairly certain are PCI-Express. > > So the question is why did I even have this problem?
Hi James, It would be interesting to see what happens if you try the 'bleeding edge' driver (http://www.ivtvdriver.org/index.php/Download#Bleeding_Edge_driver). I've made some changes about two months ago that fixed bogus TIMEOUT messages. Sometimes there are several DMA transfers needed for a frame. Depending on other DMA traffic this could trigger the timeout, even though DMA was still running. I now set the timeout for each separate DMA transfer and I've just now also increased the timeout from 100 to 300 ms. Regards, Hans > > Also is there not a better way to troubleshoot pci-latency other than > by trail and error? > > Is it possible that the default of 64 is still a little low? > > I am tempted to try a setting of latency_timer=60 just to test it. > But I am kinda tired of messing with it for now. I spent almost two > days on this. > > _______________________________________________ > ivtv-users mailing list > [email protected] > http://ivtvdriver.org/mailman/listinfo/ivtv-users _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
