This is tested and working on my Athlon XP-M 2600+ with an Epox 8KHA+ motherboard. The primary reason for its existence is that this board, despite supposedly supporting FSB multipliers up to 15x, refused to POST at anything over 12.5x. It now runs happily at 15x in Linux. (This board has since been replaced by an ASRock K7VT6, which does not seem to like changing frequency on the fly, leading to lock-ups whenever the system attempted such a change. It does, however, support the full multiplier range of the CPU.)
Warning: Athlon XP-M chips aren't intended to be used in desktop boards. Adjusting the frequency and/or voltage on the fly could crash your computer, eat your data, fry your CPU, microwave your cat and cause hideous tentacled creatures from the Dungeon Dimensions to destroy the world. Back up your data before trying this, since I can't make any guarantee it'll work for you. That said, if it does (or doesn't) work, I'd be happy to hear from you (provided you're not out to kill me after frying your motherboard).
This patch adds the following parameters to the powernow-k7
module:
| Parameter | Description |
|---|---|
msr_force |
Set to non-zero to enable MSR fallback mode. |
msr_force_latency |
Set the settling time for CPU state transitions in microseconds. The default is 200us, which should work on most systems; the minimum is 100us. If your system crashes when changing speed, you might try increasing this. |
msr_force_voltage_scaling |
Set to non-zero to enable voltage scaling when changing CPU frequency. This is disabled by default because the voltage regulators on desktop boards may well not take kindly to changing voltage while running. Enable this at your own risk. It's safer to set the core voltage in your BIOS to a value which will support the highest frequency you want to run. |
With thanks to Dave Jones for helpful advice and suitable warnings.
This patch will hopefully become obsolete as soon as the kernel.org tree gains some similar form of support.
Thanks to Joern Seeman for bringing this to my attention. He reports success with an AMD Geode CPU on an Epox 8KHA+ motherboard.
The module parameters are the same as for the original patch.
This patch adds the following parameters to the powernow-k7
module:
| Parameter | Description |
|---|---|
overwrite_table |
Set to non-zero to enable manual frequency table specification. |
multiplier |
Specifies an array of FSB multipliers, which must be multiplied by 10 (e.g. 8.5 -> 85, 10 -> 100). |
voltage |
Specifies an array of Vcore voltages corresponding to the given multipliers, in mV (e.g. 1125 -> 1.125V). |
switch_latency |
Set the settling time for CPU state transitions in microseconds. The
default is 200us, as for msr_force_latency above. |
Thanks to Hendrik for supplying this patch. If it acquires a more permanent home, I will endeavour to link to it from this page.
The module parameters are the same as for Hendrik Muhs' 2.6.8 patch.
Please note that for using the AMD Geode NX1750+ with this modified powernow-k7 module on an Abit KX7-333 board, it is advised to set the switch_latency to 300, otherwise you might experience lockups during the FID transistion.
The patch modifies the sensor detection code to search for a sensor chip which reports temperature information, rather than simply using the first chip found in the system (which in the case of my machine was an SPD EEPROM on one of my DIMMs).
adam@yggdrasl.demon.co.uk