From 28212321622d79cbab640d80d0ce0670fd9eaf72 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Fri, 28 Jun 2019 17:36:14 +0300
Subject: drm/i915: Tune down WARNs about TBT AUX power well enabling
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Git-commit: 28212321622d79cbab640d80d0ce0670fd9eaf72
Patch-mainline: v5.4-rc1
References: bsc#1152489

The HW completion flag for the TBT AUX power well enabling/disabling
gets stuck if the firmware tears down the TBT DP tunnel before the
completion.

We shouldn't complain about the timeout, since it's expected to happen
and doesn't cause further issues. We suppress the disabling timeout
already, do the same for enabling.

v2:
- Make the debug message more precise. (José)

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628143635.22066-3-imre.deak@intel.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 .../gpu/drm/i915/display/intel_display_power.c   | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index c93ad512014c..217787d10718 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -269,11 +269,17 @@ static void hsw_wait_for_power_well_enable(struct drm_i915_private *dev_priv,
 	int pw_idx = power_well->desc->hsw.idx;
 
 	/* Timeout for PW1:10 us, AUX:not specified, other PWs:20 us. */
-	WARN_ON(intel_wait_for_register(&dev_priv->uncore,
-					regs->driver,
-					HSW_PWR_WELL_CTL_STATE(pw_idx),
-					HSW_PWR_WELL_CTL_STATE(pw_idx),
-					1));
+	if (intel_wait_for_register(&dev_priv->uncore,
+				    regs->driver,
+				    HSW_PWR_WELL_CTL_STATE(pw_idx),
+				    HSW_PWR_WELL_CTL_STATE(pw_idx),
+				    1)) {
+		DRM_DEBUG_KMS("%s power well enable timeout\n",
+			      power_well->desc->name);
+
+		/* An AUX timeout is expected if the TBT DP tunnel is down. */
+		WARN_ON(!power_well->desc->hsw.is_tc_tbt);
+	}
 }
 
 static u32 hsw_power_well_requesters(struct drm_i915_private *dev_priv,
-- 
2.28.0