Hans figured out a solution in a separate email exchange with me. I thought everyone might want to hear it:
>>> I've just realized something that might be useful to check: open ivtv-driver.h, search for 'IVTV_VBI_PIO' and set it to 1 (currently it is 0). Compile, install, etc. Now see if you are getting better results capturing MPEG and sliced VBI at the same time. This change prevents the driver from using DMA for the sliced VBI, instead it copies it over using old-fashioned PCI reads. Normally this would be too slow, but sliced VBI is very small, especially if you are only capturing CC. >>> The fix has worked perfectly for me. Apparently there were DMA problems that this avoids. Thanks, Hans. Cyrus Hans Verkuil wrote: > On Thursday 31 August 2006 08:15, Cyrus A wrote: > >> Hans Verkuil wrote: >> >>> Anyway, in about two weeks time from now I hope to have a much >>> better idea on how to go forward. For now I'll just continue >>> refactoring several years worth of sometimes quite ugly code. >>> >>> Hans >>> >>> _______________________________________________ >>> ivtv-users mailing list >>> [email protected] >>> http://ivtvdriver.org/mailman/listinfo/ivtv-users >>> >> (I'll just keep the bottom-posting tradition of this thread alive...) >> >> I tried disabling cpuspeed but I don't believe it helped. It may have >> cleared up slightly, but the problem is definitely still there. >> >> I appreciate your work on this. How long do you think it'll take to >> have video/caps/sound all working simultaneously on the PVR-250 and >> 500? In time for the 2.6.18 kernel? >> > > This is unrelated to the kernel schedule, this is strictly an ivtv > driver issue. > > >> Is there anything I can do to help? If only they'd enable dog-walking >> and clothes-ironing over the internet maybe I could lighten your load >> a bit... I do have some of the sample video with the glitches in it. >> Would you like me to give it to you? >> > > As I mentioned in my previous mail, I should know more in two weeks > time. I need to clean up a lot of code before I can even begin at the > real work of improving DMA. It looks like the key factor for success is > to handle DMA as fast as possible, and that simply isn't the case right > now. > > For me it will be important to have a group of testers who are willing > to do some heavy testing once I have something solid. It will mean that > you will have to run the bleeding-edge v4l-dvb code from the > video4linux project together with my sources, something you do not want > to do on a production system. So if you can have a machine available > that can be safely used for tests like this, then that will be a big > help. > > Hans > > _______________________________________________ > 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
