blob: b8ee47a1f9cb5d576fd3035c743b321af87b5d41 [file] [log] [blame]
From 6156c74dbf521a7035984c63e178607597f64481 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <>
Date: Fri, 14 Jun 2013 14:02:52 +0300
Subject: drm/i915: Fix VLV PLL LPF coefficients for DAC
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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 <>
(cherry picked from commit 99750bd46f6ad3816fe2045a34fac432114c8196)
Signed-off-by: Darren Hart <>
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 e441a4b5904a..6901b1b466e6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4400,6 +4400,7 @@ 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),