Messages in this thread | | | Date | Sat, 17 Jan 1998 23:34:59 -0500 (EST) | From | Emil Briggs <> | Subject | Re: MTRR patch causes system lockups |
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>> The MTRR setting patch can cause a system lockup for certain >> motherboards/bioses using the Natoma chipset. I've tested this >> under two P6 motherboards so far and obtained the same results. >> Heres the conditions under which the lockup occurs. >> >> >> 1. write combining to the linear frame buffer is enabled >> 2. passive release is not enabled in the PIIX3 (bit 1 offset 82h) >> 3. access to the floppy drive at the same time as large transfers >> to the LFB are occuring. >> > >Here's a kernel patch that should fix the problem (for 2.1.75 onwards) > >Putting PCI-related code in with MTRR code is a little ugly, so I've >put the fix in drivers/pci/quirks.c instead (it is a PCI quirk, after >all). >
You're right -- it belongs in quirks. It might be a good idea to add a line to the configure help for CONFIG_MTRR -- let people know that if they have a 440FX chipset and they set CONFIG_MTTR to yes that they also need to make sure passive release is enabled.
>You'll need to say yes to CONFIG_PCI_OPTIMIZE. > >(CONFIG_PCI_OPTIMIZE is really a misnomer in 2.1.75 onwards. What do >people think of CONFIG_PCI_QUIRKS, or having a CONFIG option for each >quirk?). >
Definitely if there's a lot of quirks to take care of. So far it looks like this is the first one besides the bridge optimizations.
>Please let me know whether it does the trick. >
Works fine on 2.1.78. Not sure how many bios's have this problem. I checked two SuperMicro motherboards (a P6SNE and a P6DNE with AMI bios) and both of them failed to set the passive release bit correctly.
Emil
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