From 0336ab580878f4c5663dfa2b66095821fdc3e588 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 11 Oct 2019 23:20:30 +0300
Subject: drm/i915: Favor last VBT child device with conflicting AUX ch/DDC pin
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Git-commit: 0336ab580878f4c5663dfa2b66095821fdc3e588
Patch-mainline: v5.4-rc4
References: bsc#1152489
The first come first served apporoach to handling the VBT
child device AUX ch conflicts has backfired. We have machines
in the wild where the VBT specifies both port A eDP and
port E DP (in that order) with port E being the real one.
So let's try to flip the preference around and let the last
child device win once again.
Cc: stable@vger.kernel.org
Cc: Jani Nikula <jani.nikula@intel.com>
Tested-by: Masami Ichikawa <masami256@gmail.com>
Tested-by: Torsten <freedesktop201910@liggy.de>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111966
Fixes: 36a0f92020dc ("drm/i915/bios: make child device order the priority order")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191011202030.8829-1-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 41e35ffb380bde1379e4030bb5b2ac824d5139cf)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/i915/display/intel_bios.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index efb39f350b19..3250c1b8dcca 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -1270,7 +1270,7 @@ static void sanitize_ddc_pin(struct drm_i915_private *dev_priv,
DRM_DEBUG_KMS("port %c trying to use the same DDC pin (0x%x) as port %c, "
"disabling port %c DVI/HDMI support\n",
port_name(port), info->alternate_ddc_pin,
- port_name(p), port_name(port));
+ port_name(p), port_name(p));
/*
* If we have multiple ports supposedly sharing the
@@ -1278,9 +1278,14 @@ static void sanitize_ddc_pin(struct drm_i915_private *dev_priv,
* port. Otherwise they share the same ddc bin and
* system couldn't communicate with them separately.
*
- * Give child device order the priority, first come first
- * served.
+ * Give inverse child device order the priority,
+ * last one wins. Yes, there are real machines
+ * (eg. Asrock B250M-HDV) where VBT has both
+ * port A and port E with the same AUX ch and
+ * we must pick port E :(
*/
+ info = &dev_priv->vbt.ddi_port_info[p];
+
info->supports_dvi = false;
info->supports_hdmi = false;
info->alternate_ddc_pin = 0;
@@ -1316,7 +1321,7 @@ static void sanitize_aux_ch(struct drm_i915_private *dev_priv,
DRM_DEBUG_KMS("port %c trying to use the same AUX CH (0x%x) as port %c, "
"disabling port %c DP support\n",
port_name(port), info->alternate_aux_channel,
- port_name(p), port_name(port));
+ port_name(p), port_name(p));
/*
* If we have multiple ports supposedlt sharing the
@@ -1324,9 +1329,14 @@ static void sanitize_aux_ch(struct drm_i915_private *dev_priv,
* port. Otherwise they share the same aux channel
* and system couldn't communicate with them separately.
*
- * Give child device order the priority, first come first
- * served.
+ * Give inverse child device order the priority,
+ * last one wins. Yes, there are real machines
+ * (eg. Asrock B250M-HDV) where VBT has both
+ * port A and port E with the same AUX ch and
+ * we must pick port E :(
*/
+ info = &dev_priv->vbt.ddi_port_info[p];
+
info->supports_dp = false;
info->alternate_aux_channel = 0;
}
--
2.28.0