Based on kernel version 3.19. Page generated on 2015-02-13 21:23 EST.
1 2 If the box freezes hard with bttv ... 3 ===================================== 4 5 It might be a bttv driver bug. It also might be bad hardware. It also 6 might be something else ... 7 8 Just mailing me "bttv freezes" isn't going to help much. This README 9 has a few hints how you can help to pin down the problem. 10 11 12 bttv bugs 13 --------- 14 15 If some version works and another doesn't it is likely to be a driver 16 bug. It is very helpful if you can tell where exactly it broke 17 (i.e. the last working and the first broken version). 18 19 With a hard freeze you probably doesn't find anything in the logfiles. 20 The only way to capture any kernel messages is to hook up a serial 21 console and let some terminal application log the messages. /me uses 22 screen. See Documentation/serial-console.txt for details on setting 23 up a serial console. 24 25 Read Documentation/oops-tracing.txt to learn how to get any useful 26 information out of a register+stack dump printed by the kernel on 27 protection faults (so-called "kernel oops"). 28 29 If you run into some kind of deadlock, you can try to dump a call trace 30 for each process using sysrq-t (see Documentation/sysrq.txt). 31 This way it is possible to figure where *exactly* some process in "D" 32 state is stuck. 33 34 I've seen reports that bttv 0.7.x crashes whereas 0.8.x works rock solid 35 for some people. Thus probably a small buglet left somewhere in bttv 36 0.7.x. I have no idea where exactly, it works stable for me and a lot of 37 other people. But in case you have problems with the 0.7.x versions you 38 can give 0.8.x a try ... 39 40 41 hardware bugs 42 ------------- 43 44 Some hardware can't deal with PCI-PCI transfers (i.e. grabber => vga). 45 Sometimes problems show up with bttv just because of the high load on 46 the PCI bus. The bt848/878 chips have a few workarounds for known 47 incompatibilities, see README.quirks. 48 49 Some folks report that increasing the pci latency helps too, 50 althrought I'm not sure whenever this really fixes the problems or 51 only makes it less likely to happen. Both bttv and btaudio have a 52 insmod option to set the PCI latency of the device. 53 54 Some mainboard have problems to deal correctly with multiple devices 55 doing DMA at the same time. bttv + ide seems to cause this sometimes, 56 if this is the case you likely see freezes only with video and hard disk 57 access at the same time. Updating the IDE driver to get the latest and 58 greatest workarounds for hardware bugs might fix these problems. 59 60 61 other 62 ----- 63 64 If you use some binary-only yunk (like nvidia module) try to reproduce 65 the problem without. 66 67 IRQ sharing is known to cause problems in some cases. It works just 68 fine in theory and many configurations. Neverless it might be worth a 69 try to shuffle around the PCI cards to give bttv another IRQ or make 70 it share the IRQ with some other piece of hardware. IRQ sharing with 71 VGA cards seems to cause trouble sometimes. I've also seen funny 72 effects with bttv sharing the IRQ with the ACPI bridge (and 73 apci-enabled kernel).