From: Ville Syrjälä Date: Fri, 6 Sep 2013 20:28:58 +0000 (+0300) Subject: drm/i915: Don't factor in pixel multplier when deriving dotclock from link clock... X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1041a02f35c5f5a6c180a052281e7414d64bb04b;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git drm/i915: Don't factor in pixel multplier when deriving dotclock from link clock and M/N values We feed the non-multiplied clock to intel_link_compute_m_n(), so the opposite operation should use the same order of operations. So we just multiply by pixel_multiplier in the end now. Reviewed-by: Jani Nikula Signed-off-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 378174fffbc7..42b5fa16ec8b 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7334,20 +7334,18 @@ static void ironlake_crtc_clock_get(struct intel_crtc *crtc, struct drm_device *dev = crtc->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; enum transcoder cpu_transcoder = pipe_config->cpu_transcoder; - int link_freq, repeat; + int link_freq; u64 clock; u32 link_m, link_n; - repeat = pipe_config->pixel_multiplier; - /* * The calculation for the data clock is: - * pixel_clock = ((m/n)*(link_clock * nr_lanes * repeat))/bpp + * pixel_clock = ((m/n)*(link_clock * nr_lanes))/bpp * But we want to avoid losing precison if possible, so: - * pixel_clock = ((m * link_clock * nr_lanes * repeat)/(n*bpp)) + * pixel_clock = ((m * link_clock * nr_lanes)/(n*bpp)) * * and the link clock is simpler: - * link_clock = (m * link_clock * repeat) / n + * link_clock = (m * link_clock) / n */ /* @@ -7369,10 +7367,11 @@ static void ironlake_crtc_clock_get(struct intel_crtc *crtc, if (!link_m || !link_n) return; - clock = ((u64)link_m * (u64)link_freq * (u64)repeat); + clock = ((u64)link_m * (u64)link_freq); do_div(clock, link_n); - pipe_config->adjusted_mode.clock = clock; + pipe_config->adjusted_mode.clock = clock * + pipe_config->pixel_multiplier; } /** Returns the currently programmed mode of the given pipe. */