From 99750bd46f6ad3816fe2045a34fac432114c8196 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 14 Jun 2013 14:02:52 +0300 Subject: [PATCH] drm/i915: Fix VLV PLL LPF coefficients for DAC MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The current PLL settings produce a rather unstable picture when I hook up a VLV to my HP ZR24w display via a VGA cable. According to VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_9, we should use the the same LPF coefficients for DAC as we do for HDMI and RBR DP. And indeed that seems to cure the shivers. v2: Add the name of the relevant document to the commit message Signed-off-by: Ville Syrjälä Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d723819a450c..749d4282f5ad 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4404,6 +4404,7 @@ static void vlv_update_pll(struct intel_crtc *crtc) /* Set HBR and RBR LPF coefficients */ if (crtc->config.port_clock == 162000 || + intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) || intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI)) vlv_dpio_write(dev_priv, DPIO_LFP_COEFF(pipe), 0x005f0021); -- 2.11.0