Attachment 107624 Details for Bug 84265 – [PATCH] drm/i915: Don't trust the DP_DETECT bit for eDP ports on CHV

[patch] [PATCH] drm/i915: Don't trust the DP_DETECT bit for eDP ports on CHV

0001-drm-i915-Don-t-trust-the-DP_DETECT-bit-for-eDP-ports.patch (text/plain), 3.86 KB, created by Ville Syrjala on 2014-10-09 16:35:38 UTC

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Creator: Ville Syrjala

Created: 2014-10-09 16:35:38 UTC

Size: 3.86 KB

patch

obsolete

>From e50232e344537a8fd3c7d82845b111a2ac75727c Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
>Date: Thu, 9 Oct 2014 14:28:12 +0300
>Subject: [PATCH] drm/i915: Don't trust the DP_DETECT bit for eDP ports on CHV
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>On CHV the display DDC pins may be muxed to an alternate function if
>there's no need for DDC on a specific port, which is the case for eDP
>ports since there's no way to plug in a DP++ HDMI dongle.
>
>This causes problems when trying to determine if the port is present
>since the the DP_DETECTED bit is the latched state of the DDC SDA pin
>at boot. If the DDC pins are muxed to an alternate function the bit
>may indicate that the port isn't present.
>
>To work around this look at the VBT as well as the DP_DETECTED bit
>to determine if we should attempt registering an eDP port. Do this
>only for ports B and C since port D doesn't support eDP (no PPS/BLC).
>
>In theory someone could also wire up a normal DP port w/o DDC lines.
>That would just mean that simple DP++ HDMI dongles wouldn't work
>on such a port. With this change we would still fail to register
>such DP ports. But let's hope no one wires their board in such a way,
>and if they do we can extend the VBT checks to cover normal DP ports
>as well.
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84265
>Signed-off-by: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>---
> drivers/gpu/drm/i915/intel_display.c | 33 +++++++++++++++++++++------------
> 1 file changed, 21 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>index b5476dc..d6fc469 100644
>--- a/drivers/gpu/drm/i915/intel_display.c
>+++ b/drivers/gpu/drm/i915/intel_display.c
>@@ -12280,27 +12280,36 @@ static void intel_setup_outputs(struct drm_device *dev)
> 		if (I915_READ(PCH_DP_D) & DP_DETECTED)
> 			intel_dp_init(dev, PCH_DP_D, PORT_D);
> 	} else if (IS_VALLEYVIEW(dev)) {
>-		if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIB) & SDVO_DETECTED) {
>+		/*
>+		 * The DP_DETECTED bit is the latched state of the DDC
>+		 * SDA pin at boot. However since eDP doesn't require DDC
>+		 * (no way to plug in a DP->HDMI dongle) the DDC pins for
>+		 * eDP ports may have been muxed to an alternate function.
>+		 * Thus we can't rely on the DP_DETECTED bit alone to detect
>+		 * eDP ports. Consult the VBT as well as DP_DETECTED to
>+		 * detect eDP ports.
>+		 */
>+		if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIB) & SDVO_DETECTED)
> 			intel_hdmi_init(dev, VLV_DISPLAY_BASE + GEN4_HDMIB,
> 					PORT_B);
>-			if (I915_READ(VLV_DISPLAY_BASE + DP_B) & DP_DETECTED)
>-				intel_dp_init(dev, VLV_DISPLAY_BASE + DP_B, PORT_B);
>-		}
>+		if (I915_READ(VLV_DISPLAY_BASE + DP_B) & DP_DETECTED ||
>+		    intel_dp_is_edp(dev, PORT_B))
>+			intel_dp_init(dev, VLV_DISPLAY_BASE + DP_B, PORT_B);
> 
>-		if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIC) & SDVO_DETECTED) {
>+		if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIC) & SDVO_DETECTED)
> 			intel_hdmi_init(dev, VLV_DISPLAY_BASE + GEN4_HDMIC,
> 					PORT_C);
>-			if (I915_READ(VLV_DISPLAY_BASE + DP_C) & DP_DETECTED)
>-				intel_dp_init(dev, VLV_DISPLAY_BASE + DP_C, PORT_C);
>-		}
>+		if (I915_READ(VLV_DISPLAY_BASE + DP_C) & DP_DETECTED ||
>+		    intel_dp_is_edp(dev, PORT_C))
>+			intel_dp_init(dev, VLV_DISPLAY_BASE + DP_C, PORT_C);
> 
> 		if (IS_CHERRYVIEW(dev)) {
>-			if (I915_READ(VLV_DISPLAY_BASE + CHV_HDMID) & SDVO_DETECTED) {
>+			if (I915_READ(VLV_DISPLAY_BASE + CHV_HDMID) & SDVO_DETECTED)
> 				intel_hdmi_init(dev, VLV_DISPLAY_BASE + CHV_HDMID,
> 						PORT_D);
>-				if (I915_READ(VLV_DISPLAY_BASE + DP_D) & DP_DETECTED)
>-					intel_dp_init(dev, VLV_DISPLAY_BASE + DP_D, PORT_D);
>-			}
>+			/* eDP not supported on port D, so don't check VBT */
>+			if (I915_READ(VLV_DISPLAY_BASE + DP_D) & DP_DETECTED)
>+				intel_dp_init(dev, VLV_DISPLAY_BASE + DP_D, PORT_D);
> 		}
> 
> 		intel_dsi_init(dev);
>-- 
>2.0.4
>

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Attachments on bug 84265: 106765 | 107624

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