2012/10/27 Daniel Vetter <daniel.vetter at ffwll.ch>: > On Sat, Oct 27, 2012 at 3:03 PM, Paulo Zanoni <przanoni at gmail.com> wrote: >> 2012/10/27 Daniel Vetter <daniel.vetter at ffwll.ch>: >>> On Sat, Oct 27, 2012 at 1:51 PM, Paulo Zanoni <przanoni at gmail.com> wrote: >>>> 2012/10/26 Daniel Vetter <daniel.vetter at ffwll.ch>: >>>>> According to "Graphics BSpec: vol4g North Display Engine Registers [IVB], >>>>> Display Mode Set Sequence" We need to write the TU size register >>>>> of the fdi RX unit _before_ starting to train the link. >>>> >>>> Well, we are still writing it before training the link, but it's >>>> waaaaay before :) >>>> But I agree with the patch, it makes the code look more like our mode >>>> set sequence docs. >>> >>> Indeed, I've confused myself with the placement of the fdi pll code >>> quite a bit. I think that's actually a remnant of the pre-modeset >>> world, where we could potentially enter the modeset functions with >>> unknown states. I think I'll keep things as-is, and instead add a >>> comment to the fdi_pll function that we need to evetually move this to >>> the pch/fdi enabling ... >> >> I don't understand. Why not just apply the current patch? > > We could move the call to enable_fdi_pll to the right place, where we > enable all fdi/pch resources, instead of just the TU_SIZE write. Or do > you think that's worse? Our mode set sequence says the FDI PLL should be enabled way earlier than the other FDI/PCH resources, and that's what we currently do, so I believe it is currently being called at the "right place" or at least close to the right place. It seems RX TU_SIZE enablement is not part of the "FDI PLL enablement", but part of the "other FDI/PCH resources" enablement (at least that's that the HSW mode set sequence says), and that's why I agree with the patch. (I have the feeling I am trying to explain to you why your patch is correct...) Well, it's your patch, your choice :) > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- Paulo Zanoni
