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											2005-04-16 15:20:36 -07:00
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							|  |  |  | If the box freezes hard with bttv ... | 
					
						
							|  |  |  | ===================================== | 
					
						
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							|  |  |  | It might be a bttv driver bug.  It also might be bad hardware.  It also | 
					
						
							|  |  |  | might be something else ... | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | bttv bugs | 
					
						
							|  |  |  | --------- | 
					
						
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							|  |  |  | 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). | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | 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"). | 
					
						
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							|  |  |  | If you run into some kind of deadlock, you can try to dump a call trace | 
					
						
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											2005-11-07 01:01:03 -08:00
										 |  |  | 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. | 
					
						
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											2005-04-16 15:20:36 -07:00
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							|  |  |  | 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 alot of | 
					
						
							|  |  |  | other people.  But in case you have problems with the 0.7.x versions you | 
					
						
							|  |  |  | can give 0.8.x a try ... | 
					
						
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							|  |  |  | hardware bugs | 
					
						
							|  |  |  | ------------- | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | other | 
					
						
							|  |  |  | ----- | 
					
						
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							|  |  |  | If you use some binary-only yunk (like nvidia module) try to reproduce | 
					
						
							|  |  |  | the problem without. | 
					
						
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							|  |  |  | 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). | 
					
						
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