2015-05-07 14:38 GMT-03:00 Damien Lespiau <damien.lespiau@xxxxxxxxx>: > Currently, if an odd divider improves the deviation (minimizes it), we > take that divider. The recommendation is to prefer even dividers. The doc says "It is preferred to get as close to the DCO central frequency as possible, but using an even divider value takes precedence.", but I'm wondering if they meant "prefer even over odd in case they have the same deviation" or just "even divider is preferred as long as it's on the deviation threshold, even if there's an odd divider with minimal/no deviation". I see you implement the last option - if you don't count the possible bug mentioned on my review of patch 12. Assuming the loop order will be fixed on patch 12, and assuming you are correctly interpreting the spec, then your patch does what it says, so: Reviewed-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>. > > Signed-off-by: Damien Lespiau <damien.lespiau@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_ddi.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index 381a8c9..54344c3 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -1308,6 +1308,13 @@ skl_ddi_calculate_wrpll(int clock /* in Hz */, > dco_freq, > p); > } > + > + /* > + * If a solution is found with an even divider, prefer > + * this one. > + */ > + if (d == 0 && ctx.p) > + break; > } > } > > -- > 2.1.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Paulo Zanoni _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
