[Intel-gfx] [PATCH 02/23] drm/i915: Tune down WARNs about TBT AUX power well enabling

[Imre Deak]

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.

Cc: José Roberto de Souza <jose.souza at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_display_power.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display_power.c b/drivers/gpu/drm/i915/intel_display_power.c
index 278a7edc94f5..249a5fa55df6 100644
--- a/drivers/gpu/drm/i915/intel_display_power.c
+++ b/drivers/gpu/drm/i915/intel_display_power.c
@@ -268,11 +268,16 @@ 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 forced off\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,
-- 
2.17.1