[Intel-gfx] [PATCH v2 5/5] drm/i915: Drop uncore spinlock for reading forcewake counters

Chris Wilson chris at chris-wilson.co.uk
Wed Mar 22 12:37:27 UTC 2017


The set of available structs is not protected by the spinlock, and for
the single read we can use READ_ONCE instead.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index fcac795d4396..f30591f44d3a 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1459,17 +1459,14 @@ static int ironlake_drpc_info(struct seq_file *m)
 
 static int i915_forcewake_domains(struct seq_file *m, void *data)
 {
-	struct drm_i915_private *dev_priv = node_to_i915(m->private);
+	struct drm_i915_private *i915 = node_to_i915(m->private);
 	struct intel_uncore_forcewake_domain *fw_domain;
 	unsigned int tmp;
 
-	spin_lock_irq(&dev_priv->uncore.lock);
-	for_each_fw_domain(fw_domain, dev_priv, tmp) {
+	for_each_fw_domain(fw_domain, i915, tmp)
 		seq_printf(m, "%s.wake_count = %u\n",
 			   intel_uncore_forcewake_domain_to_str(fw_domain->id),
-			   fw_domain->wake_count);
-	}
-	spin_unlock_irq(&dev_priv->uncore.lock);
+			   READ_ONCE(fw_domain->wake_count));
 
 	return 0;
 }
-- 
2.11.0



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