Commit e7ad9878 authored Jun 26, 2015 by Damien Lespiau Committed by Daniel Vetter Jun 26, 2015

drm/i915/skl: Skip remaining dividers when deviation is 0



We can't improve a 0 deviation, so when we find such a divider, skip the
remaining ones they won't be better.

This short-circuit the search for 34 of the 373 test frequencies in the
corresponding i-g-t test (tools/skl_compute_wrpll)

v2: Place the short-circuiting code in skl_compute_wrpll() (Paulo)

(I'm sure nobody will notice the spurious removal of a blank line)

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Suggested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent 35040562

drivers/gpu/drm/i915/intel_ddi.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -1149,7 +1149,6 @@ static void skl_wrpll_try_divider(struct skl_wrpll_context *ctx,
		ctx->dco_freq = dco_freq;
		ctx->p = divider;
		}

		}

		static void skl_wrpll_get_multipliers(unsigned int p,
		@@ -1315,9 +1314,17 @@ skl_ddi_calculate_wrpll(int clock /* in Hz */,
		dco_central_freq[dco],
		dco_freq,
		p);
		/*
		* Skip the remaining dividers if we're sure to
		* have found the definitive divider, we can't
		* improve a 0 deviation.
		*/
		if (ctx.min_deviation == 0)
		goto skip_remaining_dividers;
		}
		}

		skip_remaining_dividers:
		/*
		* If a solution is found with an even divider, prefer
		* this one.