Does GK20A itself have any kind of thermal protection capabilities? Upstream SOCTHERM support is not yet available (though I have a driver in my tree), so we are thinking of disabling CPU DVFS on boards that don't have always-on active cooling for now. Same might be necessary for GPU as well.
On 10/07/14 10:34, Alexandre Courbot wrote: > This series adds support for reclocking on GK20A. The first two patches touch > the clock subsystem to allow GK20A to operate, by making the presence of the > thermal and voltage devices optional, and allowing pstates to be provided > directly instead of being probed using the BIOS (which Tegra does not have). > > The last patch adds the GK20A clock device. Arguably the clock can be seen as > a > stripped-down version of what is seen on NVE0, however instead of using NVE0 > support has been written from scratch using the ChromeOS kernel as a basis. > There are several reasons for this: > > - The ChromeOS driver uses a lookup table for the P coefficient which I could > not find in the NVE0 driver, > - Some registers that NVE0 expects to find are not present on GK20A (e.g. > 0x137120 and 0x137140), > - Calculation of MNP is done differently from what is performed in > nva3_pll_calc(), and it might be interesting to compare the two methods, > - All the same, the programming sequence is done differently in the ChromeOS > driver and NVE0 could possibly benefit from it (?) > > It would be interesting to try and merge both, but for now I prefer to have > the > two coexisting to ensure proper operation on GK20A and besure I don't break > dGPU support. :) > > Regarding the first patch, one might argue that I could as well add thermal > and voltage devices to GK20A. The reason this is not done is because these > currently depend heavily on the presence of a BIOS, and will require a rework > similar to that done in patch 2 for clocks. I would like to make sure this > approach is approved because applying it to other subdevs. > > Alexandre Courbot (3): > drm/nouveau/clk: make therm and volt devices optional > drm/nouveau/clk: support for non-BIOS pstates > drm/gk20a: reclocking support > > drivers/gpu/drm/nouveau/Makefile | 1 + > drivers/gpu/drm/nouveau/core/engine/device/nve0.c | 1 + > .../gpu/drm/nouveau/core/include/subdev/clock.h | 9 +- > drivers/gpu/drm/nouveau/core/subdev/clock/base.c | 52 +- > drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c | 670 > +++++++++++++++++++++ > drivers/gpu/drm/nouveau/core/subdev/clock/nv04.c | 4 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nv40.c | 4 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nv50.c | 2 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nva3.c | 4 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nvaa.c | 4 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nvc0.c | 4 +- > drivers/gpu/drm/nouveau/core/subdev/clock/nve0.c | 4 +- > 12 files changed, 725 insertions(+), 34 deletions(-) > create mode 100644 drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c >