sb/intel/{bd82x6x|ibexpeak}: Drop p_cnt_throttling_supported

The processor P_BLK doesn't support throttling. This behaviour could be
emulated with SMM, but instead just update the FADT to indicate no support
for legacy I/O based throttling using P_CNT.

We have _PTC defined in SSDT, which should be used in favour of P_CNT by
ACPI aware OS, so this change has no effect on modern OS.

Drop all occurences of p_cnt_throttling_supported and update autoport
to not generate it any more.

Change-Id: Iaf82518d5114d6de7cef01dca2d3087eea8ff927
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34351
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Nico Huber <nico.h@gmx.de>

46 files changed, 8 insertions, 56 deletions

diff --git a/src/mainboard/apple/macbookair4_2/devicetree.cb b/src/mainboard/apple/macbookair4_2/devicetree.cb
index 267ecb15fd..15ec61e717 100644
--- a/src/mainboard/apple/macbookair4_2/devicetree.cb
+++ b/src/mainboard/apple/macbookair4_2/devicetree.cb
@@ -38,7 +38,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x001c0301"
 			register "gen4_dec" = "0x00fc0701"
 			register "gpi7_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/asrock/b75pro3-m/devicetree.cb b/src/mainboard/asrock/b75pro3-m/devicetree.cb
index 9eba6fca82..32438a102f 100644
--- a/src/mainboard/asrock/b75pro3-m/devicetree.cb
+++ b/src/mainboard/asrock/b75pro3-m/devicetree.cb
@@ -58,7 +58,6 @@ chip northbridge/intel/sandybridge
 			register "gen1_dec" = "0x000c0291"
 			register "gen2_dec" = "0x000c0241"
 			register "gen3_dec" = "0x000c0251"
-			register "p_cnt_throttling_supported" = "0"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "0"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/asus/maximus_iv_gene-z/devicetree.cb b/src/mainboard/asus/maximus_iv_gene-z/devicetree.cb
index 4b80f393f6..0c25d4d91a 100644
--- a/src/mainboard/asus/maximus_iv_gene-z/devicetree.cb
+++ b/src/mainboard/asus/maximus_iv_gene-z/devicetree.cb
@@ -40,7 +40,6 @@ chip northbridge/intel/sandybridge
 		chip southbridge/intel/bd82x6x
 			register "c2_latency" = "101"
 			register "gen1_dec" = "0x00000295" # Super I/O HWM
-			register "p_cnt_throttling_supported" = "1"
 			register "sata_port_map" = "0x3f"
 			register "spi_lvscc" = "0x2005"
 			register "spi_uvscc" = "0x2005"
diff --git a/src/mainboard/asus/p8h61-m_lx/devicetree.cb b/src/mainboard/asus/p8h61-m_lx/devicetree.cb
index ef8071fabb..27705b91f7 100644
--- a/src/mainboard/asus/p8h61-m_lx/devicetree.cb
+++ b/src/mainboard/asus/p8h61-m_lx/devicetree.cb
@@ -40,7 +40,6 @@ chip northbridge/intel/sandybridge
 		chip southbridge/intel/bd82x6x
 			register "c2_latency" = "101"
 			register "gen1_dec" = "0x00000295" # Super I/O HWM
-			register "p_cnt_throttling_supported" = "1"
 			register "sata_port_map" = "0x33"
 			register "spi_lvscc" = "0x2005"
 			register "spi_uvscc" = "0x2005"
diff --git a/src/mainboard/asus/p8h61-m_pro/devicetree.cb b/src/mainboard/asus/p8h61-m_pro/devicetree.cb
index d3f1795f91..e791d70976 100644
--- a/src/mainboard/asus/p8h61-m_pro/devicetree.cb
+++ b/src/mainboard/asus/p8h61-m_pro/devicetree.cb
@@ -34,7 +34,6 @@ chip northbridge/intel/sandybridge
 			register "c2_latency" = "0x0065"
 			register "docking_supported" = "0"
 			register "gen1_dec" = "0x000c0291"		# HWM
-			register "p_cnt_throttling_supported" = "0"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "sata_interface_speed_support" = "0x3"
 			register "sata_port_map" = "0x33"
diff --git a/src/mainboard/compulab/intense_pc/devicetree.cb b/src/mainboard/compulab/intense_pc/devicetree.cb
index a6bcb1d7aa..6fa9e8357d 100644
--- a/src/mainboard/compulab/intense_pc/devicetree.cb
+++ b/src/mainboard/compulab/intense_pc/devicetree.cb
@@ -48,7 +48,6 @@ chip northbridge/intel/sandybridge # FIXME: check gfx.ndid and gfx.did
 			register "gen3_dec" = "0x000406f1"
 			register "gen4_dec" = "0x000c06a1"
 			register "gpi7_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/gigabyte/ga-b75m-d3h/devicetree.cb b/src/mainboard/gigabyte/ga-b75m-d3h/devicetree.cb
index ceb9279365..57b4960a12 100644
--- a/src/mainboard/gigabyte/ga-b75m-d3h/devicetree.cb
+++ b/src/mainboard/gigabyte/ga-b75m-d3h/devicetree.cb
@@ -39,7 +39,6 @@ chip northbridge/intel/sandybridge
 			register "sata_interface_speed_support" = "0x3"
 
 			register "pcie_port_coalesce" = "0"
-			register "p_cnt_throttling_supported" = "0"
 			register "docking_supported" = "0"
 			register "c2_latency" = "0x0065"
 
diff --git a/src/mainboard/google/butterfly/devicetree.cb b/src/mainboard/google/butterfly/devicetree.cb
index d8a0ee1c31..3c08b8bb60 100644
--- a/src/mainboard/google/butterfly/devicetree.cb
+++ b/src/mainboard/google/butterfly/devicetree.cb
@@ -66,7 +66,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			device pci 14.0 on end # USB 3.0 Controller
 			device pci 16.0 on end # Management Engine Interface 1
diff --git a/src/mainboard/google/link/devicetree.cb b/src/mainboard/google/link/devicetree.cb
index 1b27a69b54..ec7fb201d7 100644
--- a/src/mainboard/google/link/devicetree.cb
+++ b/src/mainboard/google/link/devicetree.cb
@@ -64,7 +64,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			device pci 16.0 on end # Management Engine Interface 1
 			device pci 16.1 off end # Management Engine Interface 2
diff --git a/src/mainboard/google/parrot/devicetree.cb b/src/mainboard/google/parrot/devicetree.cb
index 046db97585..33d3544264 100644
--- a/src/mainboard/google/parrot/devicetree.cb
+++ b/src/mainboard/google/parrot/devicetree.cb
@@ -62,7 +62,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			device pci 16.0 on end # Management Engine Interface 1
 			device pci 16.1 off end # Management Engine Interface 2
diff --git a/src/mainboard/google/stout/devicetree.cb b/src/mainboard/google/stout/devicetree.cb
index ddcf4e22d1..b9ccbf938c 100644
--- a/src/mainboard/google/stout/devicetree.cb
+++ b/src/mainboard/google/stout/devicetree.cb
@@ -73,7 +73,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			device pci 14.0 on end # USB 3.0 Controller
 			device pci 16.0 on end # Management Engine Interface 1
diff --git a/src/mainboard/hp/2570p/devicetree.cb b/src/mainboard/hp/2570p/devicetree.cb
index 79a84b73c2..c638676e54 100644
--- a/src/mainboard/hp/2570p/devicetree.cb
+++ b/src/mainboard/hp/2570p/devicetree.cb
@@ -52,7 +52,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/2760p/devicetree.cb b/src/mainboard/hp/2760p/devicetree.cb
index a301857b7a..06124ed30d 100644
--- a/src/mainboard/hp/2760p/devicetree.cb
+++ b/src/mainboard/hp/2760p/devicetree.cb
@@ -61,7 +61,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x007c0281"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/8460p/devicetree.cb b/src/mainboard/hp/8460p/devicetree.cb
index a06aea9669..6852f02710 100644
--- a/src/mainboard/hp/8460p/devicetree.cb
+++ b/src/mainboard/hp/8460p/devicetree.cb
@@ -60,7 +60,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/8470p/devicetree.cb b/src/mainboard/hp/8470p/devicetree.cb
index 471537218e..3725b08f66 100644
--- a/src/mainboard/hp/8470p/devicetree.cb
+++ b/src/mainboard/hp/8470p/devicetree.cb
@@ -61,7 +61,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/8770w/devicetree.cb b/src/mainboard/hp/8770w/devicetree.cb
index d98402c540..0a30de287b 100644
--- a/src/mainboard/hp/8770w/devicetree.cb
+++ b/src/mainboard/hp/8770w/devicetree.cb
@@ -49,7 +49,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/compaq_8200_elite_sff/devicetree.cb b/src/mainboard/hp/compaq_8200_elite_sff/devicetree.cb
index 95659beaf5..1472f84043 100644
--- a/src/mainboard/hp/compaq_8200_elite_sff/devicetree.cb
+++ b/src/mainboard/hp/compaq_8200_elite_sff/devicetree.cb
@@ -44,7 +44,6 @@ chip northbridge/intel/sandybridge
 			register "docking_supported" = "0"
 			register "gen1_dec" = "0x00fc0601"
 			register "gen2_dec" = "0x00fc0801"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/folio_9470m/devicetree.cb b/src/mainboard/hp/folio_9470m/devicetree.cb
index d626934343..cd610b6ac6 100644
--- a/src/mainboard/hp/folio_9470m/devicetree.cb
+++ b/src/mainboard/hp/folio_9470m/devicetree.cb
@@ -52,7 +52,6 @@ chip northbridge/intel/sandybridge # FIXME: check gfx.ndid and gfx.did
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/revolve_810_g1/devicetree.cb b/src/mainboard/hp/revolve_810_g1/devicetree.cb
index ad69ca27e4..32d04ea190 100644
--- a/src/mainboard/hp/revolve_810_g1/devicetree.cb
+++ b/src/mainboard/hp/revolve_810_g1/devicetree.cb
@@ -52,7 +52,6 @@ chip northbridge/intel/sandybridge # FIXME: check gfx.ndid and gfx.did
 			register "gen3_dec" = "0x00fcfe01"
 			register "gen4_dec" = "0x000402e9"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/hp/z220_sff_workstation/devicetree.cb b/src/mainboard/hp/z220_sff_workstation/devicetree.cb
index 68e7c63767..5108db4a65 100644
--- a/src/mainboard/hp/z220_sff_workstation/devicetree.cb
+++ b/src/mainboard/hp/z220_sff_workstation/devicetree.cb
@@ -44,7 +44,6 @@ chip northbridge/intel/sandybridge
 			register "docking_supported" = "0"
 			register "gen1_dec" = "0x00fc0601"
 			register "gen2_dec" = "0x00fc0801"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/intel/emeraldlake2/devicetree.cb b/src/mainboard/intel/emeraldlake2/devicetree.cb
index 4ed1f3c694..0a024b70d3 100644
--- a/src/mainboard/intel/emeraldlake2/devicetree.cb
+++ b/src/mainboard/intel/emeraldlake2/devicetree.cb
@@ -51,7 +51,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x003c0701"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			device pci 16.0 on end # Management Engine Interface 1
 			device pci 16.1 off end # Management Engine Interface 2
diff --git a/src/mainboard/kontron/ktqm77/devicetree.cb b/src/mainboard/kontron/ktqm77/devicetree.cb
index fad139a7ac..8928b87988 100644
--- a/src/mainboard/kontron/ktqm77/devicetree.cb
+++ b/src/mainboard/kontron/ktqm77/devicetree.cb
@@ -40,7 +40,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "0"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "xhci_switchable_ports"	= "0x0f"
 			register "superspeed_capable_ports"	= "0x0f"
diff --git a/src/mainboard/lenovo/l520/devicetree.cb b/src/mainboard/lenovo/l520/devicetree.cb
index 48c2ea010e..024b8f8dd1 100644
--- a/src/mainboard/lenovo/l520/devicetree.cb
+++ b/src/mainboard/lenovo/l520/devicetree.cb
@@ -46,7 +46,6 @@ chip northbridge/intel/sandybridge
 			register "gen4_dec" = "0x00000000"
 			register "gpi13_routing" = "2"
 			register "gpi6_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 1, 1, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/lenovo/s230u/devicetree.cb b/src/mainboard/lenovo/s230u/devicetree.cb
index a9e8babe6e..15d323d8b9 100644
--- a/src/mainboard/lenovo/s230u/devicetree.cb
+++ b/src/mainboard/lenovo/s230u/devicetree.cb
@@ -44,7 +44,6 @@ chip northbridge/intel/sandybridge
 			register "gen4_dec" = "0x000c06a1"
 			register "gpi13_routing" = "2"
 			register "gpi7_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 1, 0, 1, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/lenovo/t420/devicetree.cb b/src/mainboard/lenovo/t420/devicetree.cb
index c4092fe901..6deff6039c 100644
--- a/src/mainboard/lenovo/t420/devicetree.cb
+++ b/src/mainboard/lenovo/t420/devicetree.cb
@@ -68,7 +68,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			# device specific SPI configuration
 			register "spi_uvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/t420s/devicetree.cb b/src/mainboard/lenovo/t420s/devicetree.cb
index d1e3f75499..aa6cc68154 100644
--- a/src/mainboard/lenovo/t420s/devicetree.cb
+++ b/src/mainboard/lenovo/t420s/devicetree.cb
@@ -68,7 +68,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/t430/devicetree.cb b/src/mainboard/lenovo/t430/devicetree.cb
index 2731b69ec0..f7e04367c6 100644
--- a/src/mainboard/lenovo/t430/devicetree.cb
+++ b/src/mainboard/lenovo/t430/devicetree.cb
@@ -39,7 +39,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x000c06a1"
 			register "gpi13_routing" = "2"
 			register "gpi1_routing" = "2"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/lenovo/t430s/devicetree.cb b/src/mainboard/lenovo/t430s/devicetree.cb
index 21d54acf11..0c2f668897 100644
--- a/src/mainboard/lenovo/t430s/devicetree.cb
+++ b/src/mainboard/lenovo/t430s/devicetree.cb
@@ -71,7 +71,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 			register "docking_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/t520/variants/t520/devicetree.cb b/src/mainboard/lenovo/t520/variants/t520/devicetree.cb
index eff2d69304..7893daf9ec 100644
--- a/src/mainboard/lenovo/t520/variants/t520/devicetree.cb
+++ b/src/mainboard/lenovo/t520/variants/t520/devicetree.cb
@@ -63,7 +63,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 1, 0, 0, 0, 0 }"
 
diff --git a/src/mainboard/lenovo/t520/variants/w520/devicetree.cb b/src/mainboard/lenovo/t520/variants/w520/devicetree.cb
index ceca46ea84..8716046410 100644
--- a/src/mainboard/lenovo/t520/variants/w520/devicetree.cb
+++ b/src/mainboard/lenovo/t520/variants/w520/devicetree.cb
@@ -63,7 +63,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 1, 0, 0, 0, 0 }"
 
diff --git a/src/mainboard/lenovo/t530/variants/t530/devicetree.cb b/src/mainboard/lenovo/t530/variants/t530/devicetree.cb
index 335543a8f7..190539ac1f 100644
--- a/src/mainboard/lenovo/t530/variants/t530/devicetree.cb
+++ b/src/mainboard/lenovo/t530/variants/t530/devicetree.cb
@@ -62,7 +62,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
 
diff --git a/src/mainboard/lenovo/t530/variants/w530/devicetree.cb b/src/mainboard/lenovo/t530/variants/w530/devicetree.cb
index 0a80fa1d8c..0844124f0e 100644
--- a/src/mainboard/lenovo/t530/variants/w530/devicetree.cb
+++ b/src/mainboard/lenovo/t530/variants/w530/devicetree.cb
@@ -51,7 +51,6 @@ chip northbridge/intel/sandybridge
 			register "gen1_dec" = "0x007c1601"
 			register "gen2_dec" = "0x000c15e1"
 			register "gen4_dec" = "0x000c06a1"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/mainboard/lenovo/x131e/devicetree.cb b/src/mainboard/lenovo/x131e/devicetree.cb
index 21d38f5ab2..2a98a60cac 100644
--- a/src/mainboard/lenovo/x131e/devicetree.cb
+++ b/src/mainboard/lenovo/x131e/devicetree.cb
@@ -66,7 +66,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "0x0065"
-			register "p_cnt_throttling_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb b/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
index 8caa0d1a2f..288870f81d 100644
--- a/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
+++ b/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
@@ -70,7 +70,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/x201/devicetree.cb b/src/mainboard/lenovo/x201/devicetree.cb
index 6ece08bee6..bf74d710bb 100644
--- a/src/mainboard/lenovo/x201/devicetree.cb
+++ b/src/mainboard/lenovo/x201/devicetree.cb
@@ -68,7 +68,6 @@ chip northbridge/intel/nehalem
 			register "gen3_dec" = "0x1c1681"
 			register "gen4_dec" = "0x040069"
 
-			register "p_cnt_throttling_supported" = "1"
 			register "c2_latency" = "1"
 			register "docking_supported" = "1"
 
diff --git a/src/mainboard/lenovo/x220/devicetree.cb b/src/mainboard/lenovo/x220/devicetree.cb
index 360de04943..26fa1a4d1f 100644
--- a/src/mainboard/lenovo/x220/devicetree.cb
+++ b/src/mainboard/lenovo/x220/devicetree.cb
@@ -69,7 +69,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "1"
 
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
diff --git a/src/mainboard/lenovo/x230/devicetree.cb b/src/mainboard/lenovo/x230/devicetree.cb
index 4687e9ccc3..61a5468a78 100644
--- a/src/mainboard/lenovo/x230/devicetree.cb
+++ b/src/mainboard/lenovo/x230/devicetree.cb
@@ -72,7 +72,6 @@ chip northbridge/intel/sandybridge
 			# Enable zero-based linear PCIe root port functions
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
-			register "p_cnt_throttling_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
diff --git a/src/mainboard/msi/ms7707/devicetree.cb b/src/mainboard/msi/ms7707/devicetree.cb
index 4db2536148..fc23f359e3 100644
--- a/src/mainboard/msi/ms7707/devicetree.cb
+++ b/src/mainboard/msi/ms7707/devicetree.cb
@@ -21,7 +21,6 @@ chip northbridge/intel/sandybridge
 			register "docking_supported" = "0"
 			register "gen1_dec" = "0x000c0291"
 			register "gen2_dec" = "0x000c0a01"
-			register "p_cnt_throttling_supported" = "1"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
 			register "sata_port_map" = "0x33"
diff --git a/src/mainboard/roda/rv11/variants/rv11/devicetree.cb b/src/mainboard/roda/rv11/variants/rv11/devicetree.cb
index 1dfa02d317..68f2ba437f 100644
--- a/src/mainboard/roda/rv11/variants/rv11/devicetree.cb
+++ b/src/mainboard/roda/rv11/variants/rv11/devicetree.cb
@@ -66,7 +66,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "0"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 1, 0, 0, 0, 0 }"
 
-			register "p_cnt_throttling_supported" = "1"
 
 			register "xhci_overcurrent_mapping"	= "0x00080401"
 			register "xhci_switchable_ports"	= "0x0f"
diff --git a/src/mainboard/roda/rv11/variants/rw11/devicetree.cb b/src/mainboard/roda/rv11/variants/rw11/devicetree.cb
index f1016210e6..76ad9859c6 100644
--- a/src/mainboard/roda/rv11/variants/rw11/devicetree.cb
+++ b/src/mainboard/roda/rv11/variants/rw11/devicetree.cb
@@ -71,7 +71,6 @@ chip northbridge/intel/sandybridge
 			register "pcie_port_coalesce" = "0"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 1, 1 }"
 
-			register "p_cnt_throttling_supported" = "1"
 
 			register "xhci_overcurrent_mapping"	= "0x00000c03"
 			register "xhci_switchable_ports"	= "0x0f"
diff --git a/src/mainboard/samsung/lumpy/devicetree.cb b/src/mainboard/samsung/lumpy/devicetree.cb
index feae5bf1e8..1a4ecfdd54 100644
--- a/src/mainboard/samsung/lumpy/devicetree.cb
+++ b/src/mainboard/samsung/lumpy/devicetree.cb
@@ -64,7 +64,6 @@ chip northbridge/intel/sandybridge
 			register "gen3_dec" = "0x00fc1601"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			device pci 16.0 on end # Management Engine Interface 1
 			device pci 16.1 off end # Management Engine Interface 2
diff --git a/src/mainboard/samsung/stumpy/devicetree.cb b/src/mainboard/samsung/stumpy/devicetree.cb
index 060fc40bb6..034e166ca1 100644
--- a/src/mainboard/samsung/stumpy/devicetree.cb
+++ b/src/mainboard/samsung/stumpy/devicetree.cb
@@ -48,7 +48,6 @@ chip northbridge/intel/sandybridge
 			register "sata_port_map" = "0x3"
 
 			register "c2_latency" = "1"
-			register "p_cnt_throttling_supported" = "0"
 
 			register "gen1_dec" = "0x00fc1601"
 			# SuperIO range is 0x700-0x73f
diff --git a/src/mainboard/sapphire/pureplatinumh61/devicetree.cb b/src/mainboard/sapphire/pureplatinumh61/devicetree.cb
index 95c59dfca3..aff01302b2 100644
--- a/src/mainboard/sapphire/pureplatinumh61/devicetree.cb
+++ b/src/mainboard/sapphire/pureplatinumh61/devicetree.cb
@@ -50,7 +50,6 @@ chip northbridge/intel/sandybridge
 			register "gen2_dec" = "0x000c0a01"
 			register "gen3_dec" = "0x00000000"
 			register "gen4_dec" = "0x00000000"
-			register "p_cnt_throttling_supported" = "0"
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
 			register "pcie_port_coalesce" = "1"
 			register "sata_interface_speed_support" = "0x3"
diff --git a/src/southbridge/intel/bd82x6x/chip.h b/src/southbridge/intel/bd82x6x/chip.h
index 29f6881fc2..4be91522d2 100644
--- a/src/southbridge/intel/bd82x6x/chip.h
+++ b/src/southbridge/intel/bd82x6x/chip.h
@@ -82,7 +82,6 @@ struct southbridge_intel_bd82x6x_config {
 	uint8_t pcie_aspm_f6;
 	uint8_t pcie_aspm_f7;
 
-	int p_cnt_throttling_supported;
 	int c2_latency;
 	int docking_supported;
 
diff --git a/src/southbridge/intel/bd82x6x/lpc.c b/src/southbridge/intel/bd82x6x/lpc.c
index 8794602978..bd3c993912 100644
--- a/src/southbridge/intel/bd82x6x/lpc.c
+++ b/src/southbridge/intel/bd82x6x/lpc.c
@@ -768,12 +768,10 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->p_lvl3_lat = 87;
 	fadt->flush_size = 1024;
 	fadt->flush_stride = 16;
-	fadt->duty_offset = 1;
-	if (chip->p_cnt_throttling_supported) {
-		fadt->duty_width = 3;
-	} else {
-		fadt->duty_width = 0;
-	}
+	/* P_CNT not supported */
+	fadt->duty_offset = 0;
+	fadt->duty_width = 0;
+
 	fadt->day_alrm = 0xd;
 	fadt->mon_alrm = 0x00;
 	fadt->century = 0x00;
diff --git a/src/southbridge/intel/ibexpeak/lpc.c b/src/southbridge/intel/ibexpeak/lpc.c
index fa1ca92d78..c7464a05f1 100644
--- a/src/southbridge/intel/ibexpeak/lpc.c
+++ b/src/southbridge/intel/ibexpeak/lpc.c
@@ -680,12 +680,10 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->p_lvl3_lat = 87;
 	fadt->flush_size = 1024;
 	fadt->flush_stride = 16;
-	fadt->duty_offset = 1;
-	if (chip->p_cnt_throttling_supported) {
-		fadt->duty_width = 3;
-	} else {
-		fadt->duty_width = 0;
-	}
+	/* P_CNT not supported */
+	fadt->duty_offset = 0;
+	fadt->duty_width = 0;
+
 	fadt->day_alrm = 0xd;
 	fadt->mon_alrm = 0x00;
 	fadt->century = 0x32;