[coreboot] how to prevent legacy resource conflictwith multiple VGA cards
scott at notabs.org
Fri Oct 29 07:10:34 CEST 2010
From: coreboot-bounces at coreboot.org [mailto:coreboot-bounces at coreboot.org] On Behalf Of Peter Stuge
Sent: Thursday, October 28, 2010 11:44 PM
To: coreboot at coreboot.org
Subject: Re: [coreboot] how to prevent legacy resource conflictwith multiple VGA cards
]Myles Watson wrote:
]> The UMA device could check the tree for these bits and disable
]> itself, or some more code could be added to generically do the
]> same thing.
]I think it's a very good idea to have this code be generic, since it
]can apply to all chipsets with UMA.
]Scott Duplichan wrote:
]> There must be a pretty basic problem remaining because the driver
]> fails after a few seconds. Win7 reports that a kernel mode thread
]> has spent too long in the ATI driver code.
]I guess that the watchdog is those few seconds. Does graphics work
]during that time?
The high resolution display from the ATI driver is often visible
for a few seconds. But then the display appears to reset. Sometimes
the BSOD is "the device driver got stuck in an infinite loop". Other
times it is Stop 116 BSOD.
I just now tried several different video option roms. The all behave the same.
Earlier this evening I tried different memory congigurations. With 4GB (2+2),
I have an ACPI related BSOD to fix. With 3GB (2+1), a memory test fails
immediately when it gets near the end of the first GB. With a single 1GB DIMM
or a single 2 GB DIMM, the problem is the same.
]Could you use windbg to get more details, in particular find out what
]the ATI driver was trying to do?
For the infinite loop case, I captured a stack trace:
Looks like it had a hang early and some recovery attempts were unsuccessful.
To break into the initial failure might take some experimentation. I did do
the sanity check of reading a few I/O ports and they do not come back FF.
The frame buffer looks OK. I don't even know what bars are for.
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