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> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- Darren, a Tested-by would be much appreciated! Thanks, Jani. --- 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 76dc185793ce..27fe2df47d73 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); } -- 1.9.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
