[Intel-gfx] [PATCH 8/9] drm/i915: print FBC compression status on debugfs

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

We already had a few bugs in the past where FBC was compressing
nothing when it was enabled, which makes the feature quite useless.
Add this information on debugfs so the test suites can check for
regressions in this piece of the code.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 5 +++++
 drivers/gpu/drm/i915/i915_reg.h     | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e515aad..e34e021 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1510,6 +1510,11 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
 		seq_putc(m, '\n');
 	}
 
+	if (INTEL_INFO(dev_priv)->gen >= 7 && !IS_VALLEYVIEW(dev_priv))
+		seq_printf(m, "Compressing: %s\n",
+			   yesno(I915_READ(FBC_STATUS2) &
+				 FBC_COMPRESSION_MASK));
+
 	intel_runtime_pm_put(dev_priv);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 40ca873..b6db966 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1600,6 +1600,9 @@ enum punit_power_well {
 #define FBC_FENCE_OFF		0x03218 /* BSpec typo has 321Bh */
 #define FBC_TAG			0x03300
 
+#define FBC_STATUS2		0x43214
+#define  FBC_COMPRESSION_MASK	0x7ff
+
 #define FBC_LL_SIZE		(1536)
 
 /* Framebuffer compression for GM45+ */
-- 
2.1.3