From: Ville Syrj?l? <ville.syrjala at linux.intel.com> 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 Syrj?l? <ville.syrjala at linux.intel.com> --- 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 29f2c0d..465d6bc 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4405,6 +4405,7 @@ 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); -- 1.8.1.5
