1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 ============================================== 3 ===============================================================
4 Intel(R) Dynamic Platform and Thermal Framewor 4 Intel(R) Dynamic Platform and Thermal Framework Sysfs Interface
5 ============================================== 5 ===============================================================
6 6
7 :Copyright: © 2022 Intel Corporation 7 :Copyright: © 2022 Intel Corporation
8 8
9 :Author: Srinivas Pandruvada <srinivas.pandruva 9 :Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
10 10
11 Introduction 11 Introduction
12 ------------ 12 ------------
13 13
14 Intel(R) Dynamic Platform and Thermal Framewor 14 Intel(R) Dynamic Platform and Thermal Framework (DPTF) is a platform
15 level hardware/software solution for power and 15 level hardware/software solution for power and thermal management.
16 16
17 As a container for multiple power/thermal tech 17 As a container for multiple power/thermal technologies, DPTF provides
18 a coordinated approach for different policies 18 a coordinated approach for different policies to effect the hardware
19 state of a system. 19 state of a system.
20 20
21 Since it is a platform level framework, this h 21 Since it is a platform level framework, this has several components.
22 Some parts of the technology is implemented in 22 Some parts of the technology is implemented in the firmware and uses
23 ACPI and PCI devices to expose various feature 23 ACPI and PCI devices to expose various features for monitoring and
24 control. Linux has a set of kernel drivers exp 24 control. Linux has a set of kernel drivers exposing hardware interface
25 to user space. This allows user space thermal 25 to user space. This allows user space thermal solutions like
26 "Linux Thermal Daemon" to read platform specif 26 "Linux Thermal Daemon" to read platform specific thermal and power
27 tables to deliver adequate performance while k 27 tables to deliver adequate performance while keeping the system under
28 thermal limits. 28 thermal limits.
29 29
30 DPTF ACPI Drivers interface 30 DPTF ACPI Drivers interface
31 ---------------------------- 31 ----------------------------
32 32
33 :file:`/sys/bus/platform/devices/<N>/uuids`, w 33 :file:`/sys/bus/platform/devices/<N>/uuids`, where <N>
34 =INT3400|INTC1040|INTC1041|INTC10A0 34 =INT3400|INTC1040|INTC1041|INTC10A0
35 35
36 ``available_uuids`` (RO) 36 ``available_uuids`` (RO)
37 A set of UUIDs strings presenting avai 37 A set of UUIDs strings presenting available policies
38 which should be notified to the firmwa 38 which should be notified to the firmware when the
39 user space can support those policies. 39 user space can support those policies.
40 40
41 UUID strings: 41 UUID strings:
42 42
43 "42A441D6-AE6A-462b-A84B-4A8CE79027D3" 43 "42A441D6-AE6A-462b-A84B-4A8CE79027D3" : Passive 1
44 44
45 "3A95C389-E4B8-4629-A526-C52C88626BAE" 45 "3A95C389-E4B8-4629-A526-C52C88626BAE" : Active
46 46
47 "97C68AE7-15FA-499c-B8C9-5DA81D606E0A" 47 "97C68AE7-15FA-499c-B8C9-5DA81D606E0A" : Critical
48 48
49 "63BE270F-1C11-48FD-A6F7-3AF253FF3E2D" 49 "63BE270F-1C11-48FD-A6F7-3AF253FF3E2D" : Adaptive performance
50 50
51 "5349962F-71E6-431D-9AE8-0A635B710AEE" 51 "5349962F-71E6-431D-9AE8-0A635B710AEE" : Emergency call
52 52
53 "9E04115A-AE87-4D1C-9500-0F3E340BFE75" 53 "9E04115A-AE87-4D1C-9500-0F3E340BFE75" : Passive 2
54 54
55 "F5A35014-C209-46A4-993A-EB56DE7530A1" 55 "F5A35014-C209-46A4-993A-EB56DE7530A1" : Power Boss
56 56
57 "6ED722A7-9240-48A5-B479-31EEF723D7CF" 57 "6ED722A7-9240-48A5-B479-31EEF723D7CF" : Virtual Sensor
58 58
59 "16CAF1B7-DD38-40ED-B1C1-1B8A1913D531" 59 "16CAF1B7-DD38-40ED-B1C1-1B8A1913D531" : Cooling mode
60 60
61 "BE84BABF-C4D4-403D-B495-3128FD44dAC1" 61 "BE84BABF-C4D4-403D-B495-3128FD44dAC1" : HDC
62 62
63 ``current_uuid`` (RW) 63 ``current_uuid`` (RW)
64 User space can write strings from avai 64 User space can write strings from available UUIDs, one at a
65 time. 65 time.
66 66
67 :file:`/sys/bus/platform/devices/<N>/`, where 67 :file:`/sys/bus/platform/devices/<N>/`, where <N>
68 =INT3400|INTC1040|INTC1041|INTC10A0 68 =INT3400|INTC1040|INTC1041|INTC10A0
69 69
70 ``imok`` (WO) 70 ``imok`` (WO)
71 User space daemon write 1 to respond t 71 User space daemon write 1 to respond to firmware event
72 for sending keep alive notification. U 72 for sending keep alive notification. User space receives
73 THERMAL_EVENT_KEEP_ALIVE kobject ueven 73 THERMAL_EVENT_KEEP_ALIVE kobject uevent notification when
74 firmware calls for user space to respo 74 firmware calls for user space to respond with imok ACPI
75 method. 75 method.
76 76
77 ``odvp*`` (RO) 77 ``odvp*`` (RO)
78 Firmware thermal status variable value 78 Firmware thermal status variable values. Thermal tables
79 calls for different processing based o 79 calls for different processing based on these variable
80 values. 80 values.
81 81
82 ``data_vault`` (RO) 82 ``data_vault`` (RO)
83 Binary thermal table. Refer to 83 Binary thermal table. Refer to
84 https:/github.com/intel/thermal_daemon 84 https:/github.com/intel/thermal_daemon for decoding
85 thermal table. 85 thermal table.
86 86
87 ``production_mode`` (RO) 87 ``production_mode`` (RO)
88 When different from zero, manufacturer 88 When different from zero, manufacturer locked thermal configuration
89 from further changes. 89 from further changes.
90 90
91 ACPI Thermal Relationship table interface 91 ACPI Thermal Relationship table interface
92 ------------------------------------------ 92 ------------------------------------------
93 93
94 :file:`/dev/acpi_thermal_rel` 94 :file:`/dev/acpi_thermal_rel`
95 95
96 This device provides IOCTL interface t 96 This device provides IOCTL interface to read standard ACPI
97 thermal relationship tables via ACPI m 97 thermal relationship tables via ACPI methods _TRT and _ART.
98 These IOCTLs are defined in 98 These IOCTLs are defined in
99 drivers/thermal/intel/int340x_thermal/ 99 drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
100 100
101 IOCTLs: 101 IOCTLs:
102 102
103 ACPI_THERMAL_GET_TRT_LEN: Get length o 103 ACPI_THERMAL_GET_TRT_LEN: Get length of TRT table
104 104
105 ACPI_THERMAL_GET_ART_LEN: Get length o 105 ACPI_THERMAL_GET_ART_LEN: Get length of ART table
106 106
107 ACPI_THERMAL_GET_TRT_COUNT: Number of 107 ACPI_THERMAL_GET_TRT_COUNT: Number of records in TRT table
108 108
109 ACPI_THERMAL_GET_ART_COUNT: Number of 109 ACPI_THERMAL_GET_ART_COUNT: Number of records in ART table
110 110
111 ACPI_THERMAL_GET_TRT: Read binary TRT 111 ACPI_THERMAL_GET_TRT: Read binary TRT table, length to read is
112 provided via argument to ioctl(). 112 provided via argument to ioctl().
113 113
114 ACPI_THERMAL_GET_ART: Read binary ART 114 ACPI_THERMAL_GET_ART: Read binary ART table, length to read is
115 provided via argument to ioctl(). 115 provided via argument to ioctl().
116 116
117 DPTF ACPI Sensor drivers 117 DPTF ACPI Sensor drivers
118 ------------------------- 118 -------------------------
119 119
120 DPTF Sensor drivers are presented as standard 120 DPTF Sensor drivers are presented as standard thermal sysfs thermal_zone.
121 121
122 122
123 DPTF ACPI Cooling drivers 123 DPTF ACPI Cooling drivers
124 -------------------------- 124 --------------------------
125 125
126 DPTF cooling drivers are presented as standard 126 DPTF cooling drivers are presented as standard thermal sysfs cooling_device.
127 127
128 128
129 DPTF Processor thermal PCI Driver interface 129 DPTF Processor thermal PCI Driver interface
130 -------------------------------------------- 130 --------------------------------------------
131 131
132 :file:`/sys/bus/pci/devices/0000\:00\:04.0/pow 132 :file:`/sys/bus/pci/devices/0000\:00\:04.0/power_limits/`
133 133
134 Refer to Documentation/power/powercap/powercap 134 Refer to Documentation/power/powercap/powercap.rst for powercap
135 ABI. 135 ABI.
136 136
137 ``power_limit_0_max_uw`` (RO) 137 ``power_limit_0_max_uw`` (RO)
138 Maximum powercap sysfs constraint_0_po 138 Maximum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
139 139
140 ``power_limit_0_step_uw`` (RO) 140 ``power_limit_0_step_uw`` (RO)
141 Power limit increment/decrements for I 141 Power limit increment/decrements for Intel RAPL constraint 0 power limit
142 142
143 ``power_limit_0_min_uw`` (RO) 143 ``power_limit_0_min_uw`` (RO)
144 Minimum powercap sysfs constraint_0_po 144 Minimum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
145 145
146 ``power_limit_0_tmin_us`` (RO) 146 ``power_limit_0_tmin_us`` (RO)
147 Minimum powercap sysfs constraint_0_ti 147 Minimum powercap sysfs constraint_0_time_window_us for Intel RAPL
148 148
149 ``power_limit_0_tmax_us`` (RO) 149 ``power_limit_0_tmax_us`` (RO)
150 Maximum powercap sysfs constraint_0_ti 150 Maximum powercap sysfs constraint_0_time_window_us for Intel RAPL
151 151
152 ``power_limit_1_max_uw`` (RO) 152 ``power_limit_1_max_uw`` (RO)
153 Maximum powercap sysfs constraint_1_po 153 Maximum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
154 154
155 ``power_limit_1_step_uw`` (RO) 155 ``power_limit_1_step_uw`` (RO)
156 Power limit increment/decrements for I 156 Power limit increment/decrements for Intel RAPL constraint 1 power limit
157 157
158 ``power_limit_1_min_uw`` (RO) 158 ``power_limit_1_min_uw`` (RO)
159 Minimum powercap sysfs constraint_1_po 159 Minimum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
160 160
161 ``power_limit_1_tmin_us`` (RO) 161 ``power_limit_1_tmin_us`` (RO)
162 Minimum powercap sysfs constraint_1_ti 162 Minimum powercap sysfs constraint_1_time_window_us for Intel RAPL
163 163
164 ``power_limit_1_tmax_us`` (RO) 164 ``power_limit_1_tmax_us`` (RO)
165 Maximum powercap sysfs constraint_1_ti 165 Maximum powercap sysfs constraint_1_time_window_us for Intel RAPL
166 166
167 ``power_floor_status`` (RO) 167 ``power_floor_status`` (RO)
168 When set to 1, the power floor of the 168 When set to 1, the power floor of the system in the current
169 configuration has been reached. It ne 169 configuration has been reached. It needs to be reconfigured to allow
170 power to be reduced any further. 170 power to be reduced any further.
171 171
172 ``power_floor_enable`` (RW) 172 ``power_floor_enable`` (RW)
173 When set to 1, enable reading and noti 173 When set to 1, enable reading and notification of the power floor
174 status. Notifications are triggered fo 174 status. Notifications are triggered for the power_floor_status
175 attribute value changes. 175 attribute value changes.
176 176
177 :file:`/sys/bus/pci/devices/0000\:00\:04.0/` 177 :file:`/sys/bus/pci/devices/0000\:00\:04.0/`
178 178
179 ``tcc_offset_degree_celsius`` (RW) 179 ``tcc_offset_degree_celsius`` (RW)
180 TCC offset from the critical temperatu 180 TCC offset from the critical temperature where hardware will throttle
181 CPU. 181 CPU.
182 182
183 :file:`/sys/bus/pci/devices/0000\:00\:04.0/wor 183 :file:`/sys/bus/pci/devices/0000\:00\:04.0/workload_request`
184 184
185 ``workload_available_types`` (RO) 185 ``workload_available_types`` (RO)
186 Available workload types. User space c 186 Available workload types. User space can specify one of the workload type
187 it is currently executing via workload 187 it is currently executing via workload_type. For example: idle, bursty,
188 sustained etc. 188 sustained etc.
189 189
190 ``workload_type`` (RW) 190 ``workload_type`` (RW)
191 User space can specify any one of the 191 User space can specify any one of the available workload type using
192 this interface. 192 this interface.
193 193
194 DPTF Processor thermal RFIM interface 194 DPTF Processor thermal RFIM interface
195 -------------------------------------------- 195 --------------------------------------------
196 196
197 RFIM interface allows adjustment of FIVR (Full 197 RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator),
198 DDR (Double Data Rate) and DLVR (Digital Linea 198 DDR (Double Data Rate) and DLVR (Digital Linear Voltage Regulator)
199 frequencies to avoid RF interference with WiFi 199 frequencies to avoid RF interference with WiFi and 5G.
200 200
201 Switching voltage regulators (VR) generate rad 201 Switching voltage regulators (VR) generate radiated EMI or RFI at the
202 fundamental frequency and its harmonics. Some 202 fundamental frequency and its harmonics. Some harmonics may interfere
203 with very sensitive wireless receivers such as 203 with very sensitive wireless receivers such as Wi-Fi and cellular that
204 are integrated into host systems like notebook 204 are integrated into host systems like notebook PCs. One of mitigation
205 methods is requesting SOC integrated VR (IVR) 205 methods is requesting SOC integrated VR (IVR) switching frequency to a
206 small % and shift away the switching noise har 206 small % and shift away the switching noise harmonic interference from
207 radio channels. OEM or ODMs can use the drive 207 radio channels. OEM or ODMs can use the driver to control SOC IVR
208 operation within the range where it does not i 208 operation within the range where it does not impact IVR performance.
209 209
210 Some products use DLVR instead of FIVR as swit 210 Some products use DLVR instead of FIVR as switching voltage regulator.
211 In this case attributes of DLVR must be adjust 211 In this case attributes of DLVR must be adjusted instead of FIVR.
212 212
213 While shifting the frequencies additional cloc 213 While shifting the frequencies additional clock noise can be introduced,
214 which is compensated by adjusting Spread spect 214 which is compensated by adjusting Spread spectrum percent. This helps
215 to reduce the clock noise to meet regulatory c 215 to reduce the clock noise to meet regulatory compliance. This spreading
216 % increases bandwidth of signal transmission a 216 % increases bandwidth of signal transmission and hence reduces the
217 effects of interference, noise and signal fadi 217 effects of interference, noise and signal fading.
218 218
219 DRAM devices of DDR IO interface and their pow 219 DRAM devices of DDR IO interface and their power plane can generate EMI
220 at the data rates. Similar to IVR control mech 220 at the data rates. Similar to IVR control mechanism, Intel offers a
221 mechanism by which DDR data rates can be chang 221 mechanism by which DDR data rates can be changed if several conditions
222 are met: there is strong RFI interference beca 222 are met: there is strong RFI interference because of DDR; CPU power
223 management has no other restriction in changin 223 management has no other restriction in changing DDR data rates;
224 PC ODMs enable this feature (real time DDR RFI 224 PC ODMs enable this feature (real time DDR RFI Mitigation referred to as
225 DDR-RFIM) for Wi-Fi from BIOS. 225 DDR-RFIM) for Wi-Fi from BIOS.
226 226
227 227
228 FIVR attributes 228 FIVR attributes
229 229
230 :file:`/sys/bus/pci/devices/0000\:00\:04.0/fiv 230 :file:`/sys/bus/pci/devices/0000\:00\:04.0/fivr/`
231 231
232 ``vco_ref_code_lo`` (RW) 232 ``vco_ref_code_lo`` (RW)
233 The VCO reference code is an 11-bit fi 233 The VCO reference code is an 11-bit field and controls the FIVR
234 switching frequency. This is the 3-bit 234 switching frequency. This is the 3-bit LSB field.
235 235
236 ``vco_ref_code_hi`` (RW) 236 ``vco_ref_code_hi`` (RW)
237 The VCO reference code is an 11-bit fi 237 The VCO reference code is an 11-bit field and controls the FIVR
238 switching frequency. This is the 8-bit 238 switching frequency. This is the 8-bit MSB field.
239 239
240 ``spread_spectrum_pct`` (RW) 240 ``spread_spectrum_pct`` (RW)
241 Set the FIVR spread spectrum clocking 241 Set the FIVR spread spectrum clocking percentage
242 242
243 ``spread_spectrum_clk_enable`` (RW) 243 ``spread_spectrum_clk_enable`` (RW)
244 Enable/disable of the FIVR spread spec 244 Enable/disable of the FIVR spread spectrum clocking feature
245 245
246 ``rfi_vco_ref_code`` (RW) 246 ``rfi_vco_ref_code`` (RW)
247 This field is a read only status regis 247 This field is a read only status register which reflects the
248 current FIVR switching frequency 248 current FIVR switching frequency
249 249
250 ``fivr_fffc_rev`` (RW) 250 ``fivr_fffc_rev`` (RW)
251 This field indicated the revision of t 251 This field indicated the revision of the FIVR HW.
252 252
253 253
254 DVFS attributes 254 DVFS attributes
255 255
256 :file:`/sys/bus/pci/devices/0000\:00\:04.0/dvf 256 :file:`/sys/bus/pci/devices/0000\:00\:04.0/dvfs/`
257 257
258 ``rfi_restriction_run_busy`` (RW) 258 ``rfi_restriction_run_busy`` (RW)
259 Request the restriction of specific DD 259 Request the restriction of specific DDR data rate and set this
260 value 1. Self reset to 0 after operati 260 value 1. Self reset to 0 after operation.
261 261
262 ``rfi_restriction_err_code`` (RW) 262 ``rfi_restriction_err_code`` (RW)
263 0 :Request is accepted, 1:Feature disa 263 0 :Request is accepted, 1:Feature disabled,
264 2: the request restricts more points t 264 2: the request restricts more points than it is allowed
265 265
266 ``rfi_restriction_data_rate_Delta`` (RW) 266 ``rfi_restriction_data_rate_Delta`` (RW)
267 Restricted DDR data rate for RFI prote 267 Restricted DDR data rate for RFI protection: Lower Limit
268 268
269 ``rfi_restriction_data_rate_Base`` (RW) 269 ``rfi_restriction_data_rate_Base`` (RW)
270 Restricted DDR data rate for RFI prote 270 Restricted DDR data rate for RFI protection: Upper Limit
271 271
272 ``ddr_data_rate_point_0`` (RO) 272 ``ddr_data_rate_point_0`` (RO)
273 DDR data rate selection 1st point 273 DDR data rate selection 1st point
274 274
275 ``ddr_data_rate_point_1`` (RO) 275 ``ddr_data_rate_point_1`` (RO)
276 DDR data rate selection 2nd point 276 DDR data rate selection 2nd point
277 277
278 ``ddr_data_rate_point_2`` (RO) 278 ``ddr_data_rate_point_2`` (RO)
279 DDR data rate selection 3rd point 279 DDR data rate selection 3rd point
280 280
281 ``ddr_data_rate_point_3`` (RO) 281 ``ddr_data_rate_point_3`` (RO)
282 DDR data rate selection 4th point 282 DDR data rate selection 4th point
283 283
284 ``rfi_disable (RW)`` 284 ``rfi_disable (RW)``
285 Disable DDR rate change feature 285 Disable DDR rate change feature
286 286
287 DLVR attributes 287 DLVR attributes
288 288
289 :file:`/sys/bus/pci/devices/0000\:00\:04.0/dlv 289 :file:`/sys/bus/pci/devices/0000\:00\:04.0/dlvr/`
290 290
291 ``dlvr_hardware_rev`` (RO) 291 ``dlvr_hardware_rev`` (RO)
292 DLVR hardware revision. 292 DLVR hardware revision.
293 293
294 ``dlvr_freq_mhz`` (RO) 294 ``dlvr_freq_mhz`` (RO)
295 Current DLVR PLL frequency in MHz. 295 Current DLVR PLL frequency in MHz.
296 296
297 ``dlvr_freq_select`` (RW) 297 ``dlvr_freq_select`` (RW)
298 Sets DLVR PLL clock frequency. Once se 298 Sets DLVR PLL clock frequency. Once set, and enabled via
299 dlvr_rfim_enable, the dlvr_freq_mhz wi 299 dlvr_rfim_enable, the dlvr_freq_mhz will show the current
300 DLVR PLL frequency. 300 DLVR PLL frequency.
301 301
302 ``dlvr_pll_busy`` (RO) 302 ``dlvr_pll_busy`` (RO)
303 PLL can't accept frequency change when 303 PLL can't accept frequency change when set.
304 304
305 ``dlvr_rfim_enable`` (RW) 305 ``dlvr_rfim_enable`` (RW)
306 0: Disable RF frequency hopping, 1: En 306 0: Disable RF frequency hopping, 1: Enable RF frequency hopping.
307 307
308 ``dlvr_spread_spectrum_pct`` (RW) 308 ``dlvr_spread_spectrum_pct`` (RW)
309 Sets DLVR spread spectrum percent valu 309 Sets DLVR spread spectrum percent value.
310 310
311 ``dlvr_control_mode`` (RW) 311 ``dlvr_control_mode`` (RW)
312 Specifies how frequencies are spread u 312 Specifies how frequencies are spread using spread spectrum.
313 0: Down spread, 313 0: Down spread,
314 1: Spread in the Center. 314 1: Spread in the Center.
315 315
316 ``dlvr_control_lock`` (RW) 316 ``dlvr_control_lock`` (RW)
317 1: future writes are ignored. 317 1: future writes are ignored.
318 318
319 DPTF Power supply and Battery Interface 319 DPTF Power supply and Battery Interface
320 ---------------------------------------- 320 ----------------------------------------
321 321
322 Refer to Documentation/ABI/testing/sysfs-platf 322 Refer to Documentation/ABI/testing/sysfs-platform-dptf
323 323
324 DPTF Fan Control 324 DPTF Fan Control
325 ---------------------------------------- 325 ----------------------------------------
326 326
327 Refer to Documentation/admin-guide/acpi/fan_pe 327 Refer to Documentation/admin-guide/acpi/fan_performance_states.rst
328 328
329 Workload Type Hints 329 Workload Type Hints
330 ---------------------------------------- 330 ----------------------------------------
331 331
332 The firmware in Meteor Lake processor generati 332 The firmware in Meteor Lake processor generation is capable of identifying
333 workload type and passing hints regarding it t 333 workload type and passing hints regarding it to the OS. A special sysfs
334 interface is provided to allow user space to o 334 interface is provided to allow user space to obtain workload type hints from
335 the firmware and control the rate at which the 335 the firmware and control the rate at which they are provided.
336 336
337 User space can poll attribute "workload_type_i 337 User space can poll attribute "workload_type_index" for the current hint or
338 can receive a notification whenever the value 338 can receive a notification whenever the value of this attribute is updated.
339 339
340 file:`/sys/bus/pci/devices/0000:00:04.0/worklo 340 file:`/sys/bus/pci/devices/0000:00:04.0/workload_hint/`
341 Segment 0, bus 0, device 4, function 0 is rese 341 Segment 0, bus 0, device 4, function 0 is reserved for the processor thermal
342 device on all Intel client processors. So, the 342 device on all Intel client processors. So, the above path doesn't change
343 based on the processor generation. 343 based on the processor generation.
344 344
345 ``workload_hint_enable`` (RW) 345 ``workload_hint_enable`` (RW)
346 Enable firmware to send workload type 346 Enable firmware to send workload type hints to user space.
347 347
348 ``notification_delay_ms`` (RW) 348 ``notification_delay_ms`` (RW)
349 Minimum delay in milliseconds before f 349 Minimum delay in milliseconds before firmware will notify OS. This is
350 for the rate control of notifications. 350 for the rate control of notifications. This delay is between changing
351 the workload type prediction in the fi 351 the workload type prediction in the firmware and notifying the OS about
352 the change. The default delay is 1024 352 the change. The default delay is 1024 ms. The delay of 0 is invalid.
353 The delay is rounded up to the nearest 353 The delay is rounded up to the nearest power of 2 to simplify firmware
354 programming of the delay value. The re 354 programming of the delay value. The read of notification_delay_ms
355 attribute shows the effective value us 355 attribute shows the effective value used.
356 356
357 ``workload_type_index`` (RO) 357 ``workload_type_index`` (RO)
358 Predicted workload type index. User sp 358 Predicted workload type index. User space can get notification of
359 change via existing sysfs attribute ch 359 change via existing sysfs attribute change notification mechanism.
360 360
361 The supported index values and their m 361 The supported index values and their meaning for the Meteor Lake
362 processor generation are as follows: 362 processor generation are as follows:
363 363
364 0 - Idle: System performs no tasks, p 364 0 - Idle: System performs no tasks, power and idle residency are
365 consistently low for long peri 365 consistently low for long periods of time.
366 366
367 1 – Battery Life: Power is relativel 367 1 – Battery Life: Power is relatively low, but the processor may
368 still be actively performing a 368 still be actively performing a task, such as video playback for
369 a long period of time. 369 a long period of time.
370 370
371 2 – Sustained: Power level that is r 371 2 – Sustained: Power level that is relatively high for a long period
372 of time, with very few to no p 372 of time, with very few to no periods of idleness, which will
373 eventually exhaust RAPL Power 373 eventually exhaust RAPL Power Limit 1 and 2.
374 374
375 3 – Bursty: Consumes a relatively co 375 3 – Bursty: Consumes a relatively constant average amount of power, but
376 periods of relative idleness a 376 periods of relative idleness are interrupted by bursts of
377 activity. The bursts are relat 377 activity. The bursts are relatively short and the periods of
378 relative idleness between them 378 relative idleness between them typically prevent RAPL Power
379 Limit 1 from being exhausted. 379 Limit 1 from being exhausted.
380 380
381 4 – Unknown: Can't classify. 381 4 – Unknown: Can't classify.
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