drm/i915: Use DIV_ROUND_CLOSEST() to calculate dot/vco
Rounding down when calculating the dot/vco frequencies doesn't make much
sense. Round to closest should give slightly nicer answers.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4a8a2e4..5e7127b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -329,8 +329,8 @@
{
clock->m = clock->m1 * clock->m2;
clock->p = clock->p1 * clock->p2;
- clock->vco = refclk * clock->m / clock->n;
- clock->dot = clock->vco / clock->p;
+ clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n);
+ clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}
/**
@@ -430,8 +430,8 @@
{
clock->m = clock->m2 + 2;
clock->p = clock->p1 * clock->p2;
- clock->vco = refclk * clock->m / clock->n;
- clock->dot = clock->vco / clock->p;
+ clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n);
+ clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}
static uint32_t i9xx_dpll_compute_m(struct dpll *dpll)
@@ -443,8 +443,8 @@
{
clock->m = i9xx_dpll_compute_m(clock);
clock->p = clock->p1 * clock->p2;
- clock->vco = refclk * clock->m / (clock->n + 2);
- clock->dot = clock->vco / clock->p;
+ clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n + 2);
+ clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}
#define INTELPllInvalid(s) do { /* DRM_DEBUG(s); */ return false; } while (0)
