From: Jani Nikula <jani.nikula@xxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 05adaf1f101f25f40f12c29403e6488f0e45f6b6 upstream. 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@xxxxxxxxx> Reported-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx> Tested-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx> Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- 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 ee7d6491f8cd..a9a015428b8b 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -166,6 +166,8 @@ 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); } -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html