From 9ca3ba011b9f1bf7fc73a4e7dc0c9edec2aeb149 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Tue, 17 Mar 2015 11:40:05 +0200 Subject: [PATCH] drm/i915/chv: use vlv_PLL_is_optimal in chv_find_best_dpll Prepare chv_find_best_dpll to be used for BXT too, where we want to consider the error between target and calculated frequency too when choosing a better PLL configuration. No functional change. Signed-off-by: Imre Deak Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b0aa6a4784c4..60230dcf532f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -786,6 +786,16 @@ static bool vlv_PLL_is_optimal(struct drm_device *dev, int target_freq, unsigned int best_error_ppm, unsigned int *error_ppm) { + /* + * For CHV ignore the error and consider only the P value. + * Prefer a bigger P value based on HW requirements. + */ + if (IS_CHERRYVIEW(dev)) { + *error_ppm = 0; + + return calculated_clock->p > best_clock->p; + } + if (WARN_ON_ONCE(!target_freq)) return false; @@ -864,11 +874,13 @@ chv_find_best_dpll(const intel_limit_t *limit, struct intel_crtc *crtc, intel_clock_t *best_clock) { struct drm_device *dev = crtc->base.dev; + unsigned int best_error_ppm; intel_clock_t clock; uint64_t m2; int found = false; memset(best_clock, 0, sizeof(*best_clock)); + best_error_ppm = 1000000; /* * Based on hardware doc, the n always set to 1, and m1 always @@ -882,6 +894,7 @@ chv_find_best_dpll(const intel_limit_t *limit, struct intel_crtc *crtc, for (clock.p2 = limit->p2.p2_fast; clock.p2 >= limit->p2.p2_slow; clock.p2 -= clock.p2 > 10 ? 2 : 1) { + unsigned int error_ppm; clock.p = clock.p1 * clock.p2; @@ -898,12 +911,13 @@ chv_find_best_dpll(const intel_limit_t *limit, struct intel_crtc *crtc, if (!intel_PLL_is_valid(dev, limit, &clock)) continue; - /* based on hardware requirement, prefer bigger p - */ - if (clock.p > best_clock->p) { - *best_clock = clock; - found = true; - } + if (!vlv_PLL_is_optimal(dev, target, &clock, best_clock, + best_error_ppm, &error_ppm)) + continue; + + *best_clock = clock; + best_error_ppm = error_ppm; + found = true; } } -- 2.20.1