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Commit 93b525dc authored by Daniel Vetter's avatar Daniel Vetter Committed by Keith Packard
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drm/i915: fixup forcewake spinlock fallout in drpc debugfs function 



My forcewake spinlock patches have a functional conflict with Ben
Widawsky's gen6 drpc support for debugfs. Result was a benign warning
about trying to read an non-atomic variabla with atomic_read.

Note that the entire check is racy anyway and purely informational.
Also update it to reflect the forcewake voodoo changes, the kernel can
now also hold onto a forcewake reference for longer times.

Signed-Off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarBen Widawsky <ben@bwidawsk.net>
Signed-off-by: default avatarKeith Packard <keithp@keithp.com>
parent 48467a92

drivers/gpu/drm/i915/i915_debugfs.c

+8 −3
Original line number Diff line number Diff line
@@ -1075,6 +1075,7 @@ static int gen6_drpc_info(struct seq_file *m) 
	struct drm_device *dev = node->minor->dev;

	struct drm_i915_private *dev_priv = dev->dev_private;

	u32 rpmodectl1, gt_core_status, rcctl1;

	unsigned forcewake_count;

	int count=0, ret;
@@ -1082,9 +1083,13 @@ static int gen6_drpc_info(struct seq_file *m) 
	if (ret)

		return ret;



	if (atomic_read(&dev_priv->forcewake_count)) {

		seq_printf(m, "RC information inaccurate because userspace "

			      "holds a reference \n");

	spin_lock_irq(&dev_priv->gt_lock);

	forcewake_count = dev_priv->forcewake_count;

	spin_unlock_irq(&dev_priv->gt_lock);



	if (forcewake_count) {

		seq_printf(m, "RC information inaccurate because somebody "

			      "holds a forcewake reference \n");

	} else {

		/* NB: we cannot use forcewake, else we read the wrong values */

		while (count++ < 50 && (I915_READ_NOTRACE(FORCEWAKE_ACK) & 1))