drm/i915: Fix VLV DP RBR/HDMI/DAC PLL LPF coefficients

I just got confirmation that we're using some old values for the PLL
LPF coefficients for DP RBR/HDMI/DAC on VLV. The
VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_9 document lists both values
by mistake, and apparently we had picked the wrong one. Change the
coefficients to the recommended values.

Changing the value doesn't appear to destabilize the VGA output picture
even with my sensitive HP ZR24w display. Also HDMI output to my TV still
works fine.

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 01939513b8c2210166bef9f5e5695f1f1e7de093..d2b76b695349902282e6cece717c34a9e6c6c8a7 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4465,7 +4465,7 @@ static void vlv_update_pll(struct intel_crtc *crtc)
            intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) ||
            intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI))
                vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
-                                0x005f0021);
+                                0x009f0003);
        else
                vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
                                 0x00d0000f);