[Intel-gfx] [PATCH] drm/i915: Read power well status before other registers for drpc info

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Trying to read the status of the power wells right after taking forcewake
for the other register reads makes little sense. Most of the time the
power wells will still be up due to the recent forcewake. Instead do the
power well status read first, and only then read the register needing
forcewake. This way the reported power well status can actually reflect
what's going on in the system.

Cc: Deepak S <deepak.s at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 319da61..2d4f870 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1240,11 +1240,12 @@ static int vlv_drpc_info(struct seq_file *m)
 	struct drm_info_node *node = m->private;
 	struct drm_device *dev = node->minor->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 rpmodectl1, rcctl1;
+	u32 rpmodectl1, rcctl1, pw_status;
 	unsigned fw_rendercount = 0, fw_mediacount = 0;
 
 	intel_runtime_pm_get(dev_priv);
 
+	pw_status = I915_READ(VLV_GTLC_PW_STATUS);
 	rpmodectl1 = I915_READ(GEN6_RP_CONTROL);
 	rcctl1 = I915_READ(GEN6_RC_CONTROL);
 
@@ -1263,11 +1264,9 @@ static int vlv_drpc_info(struct seq_file *m)
 		   yesno(rcctl1 & (GEN7_RC_CTL_TO_MODE |
 					GEN6_RC_CTL_EI_MODE(1))));
 	seq_printf(m, "Render Power Well: %s\n",
-			(I915_READ(VLV_GTLC_PW_STATUS) &
-				VLV_GTLC_PW_RENDER_STATUS_MASK) ? "Up" : "Down");
+		   (pw_status & VLV_GTLC_PW_RENDER_STATUS_MASK) ? "Up" : "Down");
 	seq_printf(m, "Media Power Well: %s\n",
-			(I915_READ(VLV_GTLC_PW_STATUS) &
-				VLV_GTLC_PW_MEDIA_STATUS_MASK) ? "Up" : "Down");
+		   (pw_status & VLV_GTLC_PW_MEDIA_STATUS_MASK) ? "Up" : "Down");
 
 	seq_printf(m, "Render RC6 residency since boot: %u\n",
 		   I915_READ(VLV_GT_RENDER_RC6));
-- 
2.0.4