| If the box freezes hard with bttv ... | |
| ===================================== | |
| It might be a bttv driver bug. It also might be bad hardware. It also | |
| might be something else ... | |
| Just mailing me "bttv freezes" isn't going to help much. This README | |
| has a few hints how you can help to pin down the problem. | |
| bttv bugs | |
| --------- | |
| If some version works and another doesn't it is likely to be a driver | |
| bug. It is very helpful if you can tell where exactly it broke | |
| (i.e. the last working and the first broken version). | |
| With a hard freeze you probably doesn't find anything in the logfiles. | |
| The only way to capture any kernel messages is to hook up a serial | |
| console and let some terminal application log the messages. /me uses | |
| screen. See Documentation/serial-console.txt for details on setting | |
| up a serial console. | |
| Read Documentation/oops-tracing.txt to learn how to get any useful | |
| information out of a register+stack dump printed by the kernel on | |
| protection faults (so-called "kernel oops"). | |
| If you run into some kind of deadlock, you can try to dump a call trace | |
| for each process using sysrq-t (see Documentation/sysrq.txt). | |
| This way it is possible to figure where *exactly* some process in "D" | |
| state is stuck. | |
| I've seen reports that bttv 0.7.x crashes whereas 0.8.x works rock solid | |
| for some people. Thus probably a small buglet left somewhere in bttv | |
| 0.7.x. I have no idea where exactly, it works stable for me and a lot of | |
| other people. But in case you have problems with the 0.7.x versions you | |
| can give 0.8.x a try ... | |
| hardware bugs | |
| ------------- | |
| Some hardware can't deal with PCI-PCI transfers (i.e. grabber => vga). | |
| Sometimes problems show up with bttv just because of the high load on | |
| the PCI bus. The bt848/878 chips have a few workarounds for known | |
| incompatibilities, see README.quirks. | |
| Some folks report that increasing the pci latency helps too, | |
| althrought I'm not sure whenever this really fixes the problems or | |
| only makes it less likely to happen. Both bttv and btaudio have a | |
| insmod option to set the PCI latency of the device. | |
| Some mainboard have problems to deal correctly with multiple devices | |
| doing DMA at the same time. bttv + ide seems to cause this sometimes, | |
| if this is the case you likely see freezes only with video and hard disk | |
| access at the same time. Updating the IDE driver to get the latest and | |
| greatest workarounds for hardware bugs might fix these problems. | |
| other | |
| ----- | |
| If you use some binary-only yunk (like nvidia module) try to reproduce | |
| the problem without. | |
| IRQ sharing is known to cause problems in some cases. It works just | |
| fine in theory and many configurations. Neverless it might be worth a | |
| try to shuffle around the PCI cards to give bttv another IRQ or make | |
| it share the IRQ with some other piece of hardware. IRQ sharing with | |
| VGA cards seems to cause trouble sometimes. I've also seen funny | |
| effects with bttv sharing the IRQ with the ACPI bridge (and | |
| apci-enabled kernel). | |