From 4bfe6b6876a036d26a960320f1ab0bbd752c19bf Mon Sep 17 00:00:00 2001 From: Zhenyu Wang Date: Mon, 2 Nov 2009 07:52:29 +0000 Subject: [PATCH] drm/i915: Fix and cleanup DPLL calculation for Ironlake When the ideal error range can't be reached, this will safely use a most closed one. Clean up some dumb codes in DPLL function too. This fixes DPLL clock issue against one monitor at 1680x1050@60hz. Signed-off-by: Zhenyu Wang Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/intel_display.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 3ba6546b7c7f..099f420de57a 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -863,10 +863,8 @@ intel_igdng_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc, struct drm_device *dev = crtc->dev; struct drm_i915_private *dev_priv = dev->dev_private; intel_clock_t clock; - int max_n; - bool found; int err_most = 47; - found = false; + int err_min = 10000; /* eDP has only 2 clock choice, no n/m/p setting */ if (HAS_eDP) @@ -890,10 +888,9 @@ intel_igdng_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc, } memset(best_clock, 0, sizeof(*best_clock)); - max_n = limit->n.max; for (clock.p1 = limit->p1.max; clock.p1 >= limit->p1.min; clock.p1--) { /* based on hardware requriment prefer smaller n to precision */ - for (clock.n = limit->n.min; clock.n <= max_n; clock.n++) { + for (clock.n = limit->n.min; clock.n <= limit->n.max; clock.n++) { /* based on hardware requirment prefere larger m1,m2 */ for (clock.m1 = limit->m1.max; clock.m1 >= limit->m1.min; clock.m1--) { @@ -907,18 +904,18 @@ intel_igdng_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc, this_err = abs((10000 - (target*10000/clock.dot))); if (this_err < err_most) { *best_clock = clock; - err_most = this_err; - max_n = clock.n; - found = true; /* found on first matching */ goto out; + } else if (this_err < err_min) { + *best_clock = clock; + err_min = this_err; } } } } } out: - return found; + return true; } /* DisplayPort has only two frequencies, 162MHz and 270MHz */ -- 2.20.1