commit b74e08cc80325883bf4561e11cec0e83f0863728
author Stéphane Marchesin <marcheu@chromium.org> Sun Jul 05 02:00:08 2015 -0700
committer Stéphane Marchesin <marcheu@chromium.org> Mon Jul 13 15:18:27 2015 -0700
tree 3ebea2ddf816c9a02691c0e72f2be59ff8126525
parent 9099aa5e280c094154fd312f415336c1aabb4b8e

drm_hwcomposer: Convert v_refresh() to float

We convert v_refresh() to return a float and instead of storing it,
compute it on the fly from the pixel clock + htotal/vtotal. This makes
the synthetic vblank computation much more accurate.

Change-Id: I2a0becf75eaca8ace30d176fdc813f3b57ba23a5

drmmode.cpp

diff --git a/drmmode.cpp b/drmmode.cpp
index dce9803..abd3b32 100644
--- a/drmmode.cpp
+++ b/drmmode.cpp
@@ -36,7 +36,6 @@
       v_sync_end_(m->vsync_end),
       v_total_(m->vtotal),
       v_scan_(m->vscan),
-      v_refresh_(m->vrefresh),
       flags_(m->flags),
       type_(m->type),
       name_(m->name) {
@@ -55,7 +54,6 @@
       v_sync_end_(0),
       v_total_(0),
       v_scan_(0),
-      v_refresh_(0),
       flags_(0),
       type_(0),
       name_("") {
@@ -70,7 +68,7 @@
          h_total_ == m.htotal && h_skew_ == m.hskew &&
          v_display_ == m.vdisplay && v_sync_start_ == m.vsync_start &&
          v_sync_end_ == m.vsync_end && v_total_ == m.vtotal &&
-         v_scan_ == m.vscan && v_refresh_ == m.vrefresh && flags_ == m.flags &&
+         v_scan_ == m.vscan && flags_ == m.flags &&
          type_ == m.type;
 }
 
@@ -86,7 +84,6 @@
   m->vsync_end = v_sync_end_;
   m->vtotal = v_total_;
   m->vscan = v_scan_;
-  m->vrefresh = v_refresh_;
   m->flags = flags_;
   m->type = type_;
   strncpy(m->name, name_.c_str(), DRM_DISPLAY_MODE_LEN);
@@ -144,8 +141,8 @@
   return v_scan_;
 }
 
-uint32_t DrmMode::v_refresh() const {
-  return v_refresh_;
+float DrmMode::v_refresh() const {
+  return clock_ / (float)(v_total_ * h_total_) * 1000.0f;
 }
 
 uint32_t DrmMode::flags() const {