[Intel-gfx] [PATCH] drm/i915: Missed lock change with rps lock

[Ben Widawsky]

Fixes a WARN_ON in igt/tests/debugfs_reader

CC: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e842dea..09bc24c 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1108,8 +1108,10 @@ static int gen6_drpc_info(struct seq_file *m)
 
 	rpmodectl1 = I915_READ(GEN6_RP_CONTROL);
 	rcctl1 = I915_READ(GEN6_RC_CONTROL);
-	sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
 	mutex_unlock(&dev->struct_mutex);
+	mutex_lock(&dev_priv->rps.hw_lock);
+	sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
+	mutex_unlock(&dev_priv->rps.hw_lock);
 
 	seq_printf(m, "Video Turbo Mode: %s\n",
 		   yesno(rpmodectl1 & GEN6_RP_MEDIA_TURBO));
-- 
1.8.0