From 05adaf1f101f25f40f12c29403e6488f0e45f6b6 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Fri, 9 May 2014 14:52:34 +0300
Subject: [PATCH] drm/i915/vlv: reset VLV media force wake request register
Media force wake get hangs the machine when the system is booted without
displays attached. The assumption is that (at least some versions of)
the firmware has skipped some initialization in that case.
Empirical evidence suggests we need to reset the media force wake
request register in addition to the render one to avoid hangs.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75895
Reported-by: Imre Deak <imre.deak@intel.com>
Reported-by: Darren Hart <dvhart@linux.intel.com>
Tested-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
drivers/gpu/drm/i915/intel_uncore.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index f729dc71d5be..d0c75779d3f6 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -185,6 +185,8 @@ static void vlv_force_wake_reset(struct drm_i915_private *dev_priv)
{
__raw_i915_write32(dev_priv, FORCEWAKE_VLV,
_MASKED_BIT_DISABLE(0xffff));
+ __raw_i915_write32(dev_priv, FORCEWAKE_MEDIA_VLV,
+ _MASKED_BIT_DISABLE(0xffff));
/* something from same cacheline, but !FORCEWAKE_VLV */
__raw_posting_read(dev_priv, FORCEWAKE_ACK_VLV);
}
--
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