On Thu, Jul 10, 2014 at 09:34:34AM +0200, 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. I think this should use CCF so we can use pre and post rate change notifiers to hookup vdd_gpu DVS. Thanks, Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
