Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/74376 )
Change subject: [RFC]soc/intel/cannonlake: Use regular NEM for CAR ......................................................................
[RFC]soc/intel/cannonlake: Use regular NEM for CAR
It was found that some coffeelake CPUs like Intel i3 9100E fail to enter CAR mode because some MSR used by NEM enhanced are lacking. According to the Intel SDM CPUID.EAX=07h.ECX=0 reg EBX[12 or 15] should indicate the presence of IA32_PAR_ASSOC and CPUID.EAX=10h.ECX[1 or 2] reg ECX[2] should indicate IA32_L3_QOS_CFG and IA32_L2_QOS_CFG respectively but even on a Intel coffeelake CPU that works with the NEM_ENHANCED these CPUID bits are all 0 so there is no way of knowing whether NEM_ENHANCED will work at runtime. Instead just always use regular NEM.
Change-Id: I141cf1543eb59bce86528012a6549101d5911865 Signed-off-by: Arthur Heymans arthur@aheymans.xyz --- M src/soc/intel/cannonlake/Kconfig 1 file changed, 20 insertions(+), 1 deletion(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/76/74376/1
diff --git a/src/soc/intel/cannonlake/Kconfig b/src/soc/intel/cannonlake/Kconfig index c4855da..1919442 100644 --- a/src/soc/intel/cannonlake/Kconfig +++ b/src/soc/intel/cannonlake/Kconfig @@ -71,7 +71,7 @@ select HAVE_HYPERTHREADING select HAVE_SMI_HANDLER select IDT_IN_EVERY_STAGE - select INTEL_CAR_NEM_ENHANCED + select INTEL_CAR_NEM select INTEL_DESCRIPTOR_MODE_CAPABLE select INTEL_GMA_ACPI select INTEL_GMA_ADD_VBT if RUN_FSP_GOP