Kconfig 5.8 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180
  1. config CPU_FREQ
  2. bool "CPU Frequency scaling"
  3. help
  4. CPU Frequency scaling allows you to change the clock speed of
  5. CPUs on the fly. This is a nice method to save power, because
  6. the lower the CPU clock speed, the less power the CPU consumes.
  7. Note that this driver doesn't automatically change the CPU
  8. clock speed, you need to either enable a dynamic cpufreq governor
  9. (see below) after boot, or use a userspace tool.
  10. For details, take a look at <file:Documentation/cpu-freq>.
  11. If in doubt, say N.
  12. if CPU_FREQ
  13. config CPU_FREQ_TABLE
  14. tristate
  15. config CPU_FREQ_STAT
  16. tristate "CPU frequency translation statistics"
  17. select CPU_FREQ_TABLE
  18. default y
  19. help
  20. This driver exports CPU frequency statistics information through sysfs
  21. file system.
  22. To compile this driver as a module, choose M here: the
  23. module will be called cpufreq_stats.
  24. If in doubt, say N.
  25. config CPU_FREQ_STAT_DETAILS
  26. bool "CPU frequency translation statistics details"
  27. depends on CPU_FREQ_STAT
  28. help
  29. This will show detail CPU frequency translation table in sysfs file
  30. system.
  31. If in doubt, say N.
  32. choice
  33. prompt "Default CPUFreq governor"
  34. default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110
  35. default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  36. help
  37. This option sets which CPUFreq governor shall be loaded at
  38. startup. If in doubt, select 'performance'.
  39. config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  40. bool "performance"
  41. select CPU_FREQ_GOV_PERFORMANCE
  42. help
  43. Use the CPUFreq governor 'performance' as default. This sets
  44. the frequency statically to the highest frequency supported by
  45. the CPU.
  46. config CPU_FREQ_DEFAULT_GOV_POWERSAVE
  47. bool "powersave"
  48. depends on EXPERT
  49. select CPU_FREQ_GOV_POWERSAVE
  50. help
  51. Use the CPUFreq governor 'powersave' as default. This sets
  52. the frequency statically to the lowest frequency supported by
  53. the CPU.
  54. config CPU_FREQ_DEFAULT_GOV_USERSPACE
  55. bool "userspace"
  56. select CPU_FREQ_GOV_USERSPACE
  57. help
  58. Use the CPUFreq governor 'userspace' as default. This allows
  59. you to set the CPU frequency manually or when a userspace
  60. program shall be able to set the CPU dynamically without having
  61. to enable the userspace governor manually.
  62. config CPU_FREQ_DEFAULT_GOV_ONDEMAND
  63. bool "ondemand"
  64. select CPU_FREQ_GOV_ONDEMAND
  65. select CPU_FREQ_GOV_PERFORMANCE
  66. help
  67. Use the CPUFreq governor 'ondemand' as default. This allows
  68. you to get a full dynamic frequency capable system by simply
  69. loading your cpufreq low-level hardware driver.
  70. Be aware that not all cpufreq drivers support the ondemand
  71. governor. If unsure have a look at the help section of the
  72. driver. Fallback governor will be the performance governor.
  73. config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
  74. bool "conservative"
  75. select CPU_FREQ_GOV_CONSERVATIVE
  76. select CPU_FREQ_GOV_PERFORMANCE
  77. help
  78. Use the CPUFreq governor 'conservative' as default. This allows
  79. you to get a full dynamic frequency capable system by simply
  80. loading your cpufreq low-level hardware driver.
  81. Be aware that not all cpufreq drivers support the conservative
  82. governor. If unsure have a look at the help section of the
  83. driver. Fallback governor will be the performance governor.
  84. endchoice
  85. config CPU_FREQ_GOV_PERFORMANCE
  86. tristate "'performance' governor"
  87. help
  88. This cpufreq governor sets the frequency statically to the
  89. highest available CPU frequency.
  90. To compile this driver as a module, choose M here: the
  91. module will be called cpufreq_performance.
  92. If in doubt, say Y.
  93. config CPU_FREQ_GOV_POWERSAVE
  94. tristate "'powersave' governor"
  95. help
  96. This cpufreq governor sets the frequency statically to the
  97. lowest available CPU frequency.
  98. To compile this driver as a module, choose M here: the
  99. module will be called cpufreq_powersave.
  100. If in doubt, say Y.
  101. config CPU_FREQ_GOV_USERSPACE
  102. tristate "'userspace' governor for userspace frequency scaling"
  103. help
  104. Enable this cpufreq governor when you either want to set the
  105. CPU frequency manually or when a userspace program shall
  106. be able to set the CPU dynamically, like on LART
  107. <http://www.lartmaker.nl/>.
  108. To compile this driver as a module, choose M here: the
  109. module will be called cpufreq_userspace.
  110. For details, take a look at <file:Documentation/cpu-freq/>.
  111. If in doubt, say Y.
  112. config CPU_FREQ_GOV_ONDEMAND
  113. tristate "'ondemand' cpufreq policy governor"
  114. select CPU_FREQ_TABLE
  115. help
  116. 'ondemand' - This driver adds a dynamic cpufreq policy governor.
  117. The governor does a periodic polling and
  118. changes frequency based on the CPU utilization.
  119. The support for this governor depends on CPU capability to
  120. do fast frequency switching (i.e, very low latency frequency
  121. transitions).
  122. To compile this driver as a module, choose M here: the
  123. module will be called cpufreq_ondemand.
  124. For details, take a look at linux/Documentation/cpu-freq.
  125. If in doubt, say N.
  126. config CPU_FREQ_GOV_CONSERVATIVE
  127. tristate "'conservative' cpufreq governor"
  128. depends on CPU_FREQ
  129. help
  130. 'conservative' - this driver is rather similar to the 'ondemand'
  131. governor both in its source code and its purpose, the difference is
  132. its optimisation for better suitability in a battery powered
  133. environment. The frequency is gracefully increased and decreased
  134. rather than jumping to 100% when speed is required.
  135. If you have a desktop machine then you should really be considering
  136. the 'ondemand' governor instead, however if you are using a laptop,
  137. PDA or even an AMD64 based computer (due to the unacceptable
  138. step-by-step latency issues between the minimum and maximum frequency
  139. transitions in the CPU) you will probably want to use this governor.
  140. To compile this driver as a module, choose M here: the
  141. module will be called cpufreq_conservative.
  142. For details, take a look at linux/Documentation/cpu-freq.
  143. If in doubt, say N.
  144. endif # CPU_FREQ