More ATI Radeon KMS Power Management Fun
Written by Michael Larabel in AMD on 14 March 2010 at 08:51 PM EDT. 19 Comments
Power management support within the Linux kernel for the ATI Radeon DRM driver has been in development for months and gone through several revisions, but with the forthcoming Linux 2.6.34 kernel there is initial ATI KMS power management support. For making the power management situation even better, over the weekend Alex Deucher of AMD has been working on another set of patches.

In the newest set of ATI power management patches that are available from his personal directory is a patch-set that can be applied against the drm-radeon-testing tree and it begins to utilize the I2C support (also introduced in the Linux 2.6.34 kernel for the ATI DRM) for poking the thermal chips.

Namely these thirteen new patches implement GUI idle IRQ support, support for changing the GPU clocks when the engine is idle, support for turning down the number of active SIMDS when running in a lower power stage for the ATI R600 ASICs and later, and new ASIC specific callback functions.

While this is a good step forward, still on Alex's plate is support for resetting the GPU clocks to the default when the kernel module is unloaded, module support for hwmon i2c thermal chip drivers, hwmon support for monitoring the core temperature and fan speeds on select ATI R600/700 (Radeon HD 2000/3000/4000 series) graphics cards, more robust power state selection, and allow power state selection to be tied to external events such as plugging/unplugging your notebook. Some core areas that also still need to be hooked in is support for memory re-clocking, changing PCI Express lane settings, and voltage adjustments.

Alex announced this newest ATI power management work moments ago on the DRI development list.

About The Author
Author picture

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter or contacted via

Related AMD News
Popular News
Trending Reviews & Featured Articles