[coreboot] Crazy Intel graphics mtrr
joe at settoplinux.org
joe at settoplinux.org
Thu Apr 17 02:03:41 CEST 2008
Hello,
I am noticing some X problems (slow, crashes once and a while) on the RCA RM4100. I think this is related to the crazy way coreboot setup the mtrr. For some reason when the Intel onboard graphics are enabled, coreboot sets up this crazy looking mtrr. I don't think they should all be write-back? Isn't write-combining faster for graphics? Does it need to have a uncachable area?
coreboot onboard graphics disabled
[root at localhost ~]# cat /proc/mtrr
reg00: base=0x00000000 ( 0MB), size= 128MB: write-back, count=1
coreboot onboard graphics enabled
[root at localhost ~]# cat /proc/mtrr
reg00: base=0x00000000 ( 0MB), size= 64MB: write-back, count=1
reg01: base=0x04000000 ( 64MB), size= 32MB: write-back, count=1
reg02: base=0x06000000 ( 96MB), size= 16MB: write-back, count=1
reg03: base=0x07000000 ( 112MB), size= 8MB: write-back, count=1
factory bios onboard graphics enabled
[root at localhost ~]# cat /proc/mtrr
reg00: base=0x07800000 ( 120MB), size= 8MB: uncachable, count=1
reg01: base=0x00000000 ( 0MB), size= 128MB: write-back, count=1
reg02: base=0xf0000000 (3840MB), size= 128MB: write-combining, count=3
--
Thanks,
Joseph Smith
Set-Top-Linux
www.settoplinux.org
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