drm/i915: Relax RPS contraints to allows setting minfreq on idle

When we idle, we set the GPU frequency to the hardware minimum (not user
minimum). We introduce a new variable to distinguish between the
different roles, and to allow easy tuning of the idle frequency without
impacting over aspects of RPS. Setting the minimum frequency should be a
safety blanket as the pcu on the GPU should be power gating itself
anyway. However, in order for us to do set the absolute minimum
frequency, we need to relax a few of our assertions that we do not
exceed the user limits.

v2: Add idle_freq
v3: Init idle_freq for vlv and add a bunch of WARNs

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Deepak S <deepak.s@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index aaf756047a20..007c7d7d8295 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1200,6 +1200,9 @@ static int i915_frequency_info(struct seq_file *m, void *unused)
 
 		seq_printf(m, "Max overclocked frequency: %dMHz\n",
 			   intel_gpu_freq(dev_priv, dev_priv->rps.max_freq));
+
+		seq_printf(m, "Idle freq: %d MHz\n",
+			   intel_gpu_freq(dev_priv, dev_priv->rps.idle_freq));
 	} else if (IS_VALLEYVIEW(dev)) {
 		u32 freq_sts;
 
@@ -1214,6 +1217,9 @@ static int i915_frequency_info(struct seq_file *m, void *unused)
 		seq_printf(m, "min GPU freq: %d MHz\n",
 			   intel_gpu_freq(dev_priv, dev_priv->rps.min_freq));
 
+		seq_printf(m, "idle GPU freq: %d MHz\n",
+			   intel_gpu_freq(dev_priv, dev_priv->rps.idle_freq));
+
 		seq_printf(m,
 			   "efficient (RPe) frequency: %d MHz\n",
 			   intel_gpu_freq(dev_priv, dev_priv->rps.efficient_freq));