On 5/2/06, Ronald G Minnich rminnich@lanl.gov wrote:
Richard Smith wrote:
Did you disable the SMI interrupt trap for access to VGA registers? That may be getting fired and tripping things up.
Man, this is a weird one.
Disabling SMI on this thing can be touchy. Steve?
I think we are ok. There is no SMM in the whole system. The GX1 actually has real PCI config space registers. And since he has an external VGA VSA isn't necessary to do any of the VGA stuff. But Steve's previous mail on _completely_ disabling the internal VGA of the cs5530 also mentioned that for an external setup some SMM trap needs to be disabled.
I just went back and re-read steve's mail:
If the F4 Video Configuration trap bit (F0, Index 42h, bit 1) is set,
the system will generate >SMIs when trying to access the PCI header registers. This should be clear for a non-SMM >system.
So he was talking about PCI acceses not generic IO accesses. Not what I was thinking.
What I was thinking of was the power mangement traps on the the IO access. But I just looked at the datasheet and they default to disabled. So unless we are turning them on I don't think they are enabled.
So its crashing 'inside' of a printk. 0x3cf is a VGA index register.
Well, I think so. Many logs looks like the one above. The first character is printed. Than nothing no more.
Man, this just smells like some sort of interrupt problem. Can we have printk do a cli() and disable all interrupts when it runs?
-- Richard A. Smith