[Intel-gfx] [PATCH v2] drm/i915: Show actual alongside requested frequency in debugfs/i915_rps_boost_info

[Chris Wilson]

Previously we hesitated in adding the hw probe for the actual GPU
frequency for rps_boost as it is quite cumbersome, but given some
surprising HW behaviour it would be useful to know both the RPS boost
state and the actual HW state in one location.

v2: vlv/chv needs more tlc

Reported-by: Tomi Sarvela <tomi.p.sarvela at intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index b4744a68cd88..f42e93b71e67 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2215,8 +2215,23 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
 	struct drm_i915_private *dev_priv = node_to_i915(m->private);
 	struct drm_device *dev = &dev_priv->drm;
 	struct intel_rps *rps = &dev_priv->gt_pm.rps;
+	u32 act_freq = rps->cur_freq;
 	struct drm_file *file;
 
+	if (intel_runtime_pm_get_if_in_use(dev_priv)) {
+		if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
+			mutex_lock(&dev_priv->pcu_lock);
+			act_freq = vlv_punit_read(dev_priv,
+						  PUNIT_REG_GPU_FREQ_STS);
+			act_freq = (act_freq >> 8) & 0xff;
+			mutex_unlock(&dev_priv->pcu_lock);
+		} else {
+			act_freq = intel_get_cagf(dev_priv,
+						  I915_READ(GEN6_RPSTAT1));
+		}
+		intel_runtime_pm_put(dev_priv);
+	}
+
 	seq_printf(m, "RPS enabled? %d\n", rps->enabled);
 	seq_printf(m, "GPU busy? %s [%d requests]\n",
 		   yesno(dev_priv->gt.awake), dev_priv->gt.active_requests);
@@ -2224,8 +2239,9 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
 	seq_printf(m, "Boosts outstanding? %d\n",
 		   atomic_read(&rps->num_waiters));
 	seq_printf(m, "Interactive? %d\n", READ_ONCE(rps->power.interactive));
-	seq_printf(m, "Frequency requested %d\n",
-		   intel_gpu_freq(dev_priv, rps->cur_freq));
+	seq_printf(m, "Frequency requested %d, actual %d\n",
+		   intel_gpu_freq(dev_priv, rps->cur_freq),
+		   intel_gpu_freq(dev_priv, act_freq));
 	seq_printf(m, "  min hard:%d, soft:%d; max soft:%d, hard:%d\n",
 		   intel_gpu_freq(dev_priv, rps->min_freq),
 		   intel_gpu_freq(dev_priv, rps->min_freq_softlimit),
-- 
2.19.0