[ltp] T60p idle GPU temperature?

Alex Deucher linux-thinkpad@linux-thinkpad.org
Thu, 12 Jul 2012 12:43:01 -0400

On Thu, Jul 12, 2012 at 12:38 PM, Henrique de Moraes Holschuh
<hmh@hmh.eng.br> wrote:
> On Thu, 12 Jul 2012, Alex Deucher wrote:
>> > No.  Either it never switched the number of lanes, or it somehow avoided
>> > whatever causes the Intel 915PM in my T43 to SERR.  If the code is exactly
>> > equal, and it DID change the PCIe link width just like modern KMS does, then
>> > the usermode->kernel mode transition was somehow helpful.
>> Might be the size of the step.  IIRC, the UMS code switched between 16
>> and 4 lanes, while the KMS code switches between 16 and however many
>> lanes are specified in the power low mode (usually 1).
> Ok, that's easy to test.  I will mangle the drm driver in 3.0 to a
> minimum of 4 lanes and test it.
> I notice the relevant code (in 3.0.36) says "FIXME: wait for idle".
> Can't that be it?

That comment should be removed.  The radeon PM core code already takes
the engine locks and makes sure the GPU is idle before changing the
power state.