[Intel-gfx] [PATCH] drm/i915: Fix VLV PLL LPF coefficients for DAC

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <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 some docs, 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.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
With this the hybrid PLL mode patch can be dropped.

 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