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authorPatrick Rudolph <patrick.rudolph@9elements.com>2024-03-30 19:06:20 +0100
committerFelix Held <felix-coreboot@felixheld.de>2024-04-22 15:31:15 +0000
commit62535b66e64ff72229645931a7f5a08147095fc7 (patch)
tree75476a4aac60c71f9149ee783084d6cc73d71e1a /src/mainboard/lenovo/x220
parent2d89c7821744de70e5bddd3a1659dd43c4be5d4e (diff)
cpu/intel/model_206ax: Allow to configure VR settings
Allow to set board specific CPU voltage regulator settings. The VR12 compatible voltage regulator for the CPU can be configured by two MSRs. Currently a default value is applied, which mimics the Intel reference code and is what the BWG suggest. However most board vendors fill in the actual VR parameters to support OC or ULV board variants. When the mainboard design is too different from the Intel reference design, not updating the VR settings might result in: - unstable system behaviour - limited turbo performance - excessive battery drain - no over-clocking capability This patch adds support to set the board specific current limit for Icc and Igfx. It also allows to adjust PSI1, PSI2 and PSI3, which are powerstates used by the VR, that consume less energy when the system is idle. Test on Lenovo X220 with full CPU load after 1 minute, compared to previous code with default settings: - Limiting PP0 max current below Iccmax results in less CPU performance. RAPL readings show that less power is drawn over time. - Limiting PP0 max current to Iccmax results in equal CPU performance. RAPL readings show that the same power is drawn over time. - Setting the PP0 max current to a value >> Iccmax results in equal CPU performance. RAPL readings show that the same power is drawn over time. - Updating the MSR at runtime has no effect. Change-Id: I59edab47fc4fbe0240e1dd7d25647f7549b4def2 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/81597 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Diffstat (limited to 'src/mainboard/lenovo/x220')
-rw-r--r--src/mainboard/lenovo/x220/devicetree.cb14
1 files changed, 14 insertions, 0 deletions
diff --git a/src/mainboard/lenovo/x220/devicetree.cb b/src/mainboard/lenovo/x220/devicetree.cb
index 233f69082f..dc2f4a5858 100644
--- a/src/mainboard/lenovo/x220/devicetree.cb
+++ b/src/mainboard/lenovo/x220/devicetree.cb
@@ -35,6 +35,20 @@ chip northbridge/intel/sandybridge
{ 1, 7, 0x0080 },
{ 1, 6, 0x0080 },}"
+ chip cpu/intel/model_206ax
+ # Values obtained from vendor BIOS v1.46
+ # schematics say 33Amps for 17W TDP, 53Amps for 35W TDP
+ register "pp0_current_limit" = "98"
+ # schematics say 33Amps for GFX
+ register "pp1_current_limit" = "33"
+ register "pp0_psi[VR12_PSI1]" = "{VR12_2_PHASES, 20}"
+ register "pp0_psi[VR12_PSI2]" = "{VR12_ALL_PHASES, 5}"
+ register "pp0_psi[VR12_PSI3]" = "{VR12_ALL_PHASES, 1}"
+ register "pp1_psi[VR12_PSI1]" = "{VR12_2_PHASES, 20}"
+ register "pp1_psi[VR12_PSI2]" = "{VR12_ALL_PHASES, 5}"
+ register "pp1_psi[VR12_PSI3]" = "{VR12_ALL_PHASES, 1}"
+ device cpu_cluster 0 on end
+ end
device domain 0 on
subsystemid 0x17aa 0x21db inherit