commit c07b21121553f981a1888bb855c987138879c267
author Sean Paul <seanpaul@chromium.org> Tue Nov 17 16:38:10 2015 -0500
committer Sean Paul <seanpaul@chromium.org> Thu Nov 19 14:42:27 2015 -0500
tree d1ddd56b71a5d0d7fdc1ef79e4a3cf47ef9aa726
parent 35301f498c372f3ad2bbbc969acda39056131b26

drm_hwcomposer: Add test_only mode to CommitFrame

Allow the caller of CommitFrame to run the commit in "test only" mode
which will send the frame to the kernel, but won't actually change any
registers.

Bug: 25379136
Test: Tested on smaug

Change-Id: I831b5f17d433bc60d9f107689feb1d7672c100a9
Signed-off-by: Sean Paul <seanpaul@chromium.org>

drmdisplaycompositor.cpp

diff --git a/drmdisplaycompositor.cpp b/drmdisplaycompositor.cpp
index bcd1a14..7c26343 100644
--- a/drmdisplaycompositor.cpp
+++ b/drmdisplaycompositor.cpp
@@ -593,7 +593,8 @@
   return ret;
 }
 
-int DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp) {
+int DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp,
+                                      bool test_only) {
   ATRACE_CALL();
 
   int ret = 0;
@@ -660,7 +661,7 @@
           break;
         }
         DrmHwcLayer &layer = layers[comp_plane.source_layer];
-        if (layer.acquire_fence.get() >= 0) {
+        if (!test_only && layer.acquire_fence.get() >= 0) {
           int acquire_fence = layer.acquire_fence.get();
           for (int i = 0; i < kAcquireWaitTries; ++i) {
             ret = sync_wait(acquire_fence, kAcquireWaitTimeoutMs);
@@ -788,10 +789,16 @@
 
 out:
   if (!ret) {
-    ret = drmModePropertySetCommit(drm_->fd(), DRM_MODE_ATOMIC_ALLOW_MODESET,
-                                   drm_, pset);
+    uint32_t flags = DRM_MODE_ATOMIC_ALLOW_MODESET;
+    if (test_only)
+      flags |= DRM_MODE_ATOMIC_TEST_ONLY;
+
+    ret = drmModePropertySetCommit(drm_->fd(), flags, drm_, pset);
     if (ret) {
-      ALOGE("Failed to commit pset ret=%d\n", ret);
+      if (test_only)
+        ALOGI("Commit test pset failed ret=%d\n", ret);
+      else
+        ALOGE("Failed to commit pset ret=%d\n", ret);
       drmModePropertySetFree(pset);
       return ret;
     }
@@ -799,7 +806,7 @@
   if (pset)
     drmModePropertySetFree(pset);
 
-  if (mode_.needs_modeset) {
+  if (!test_only && mode_.needs_modeset) {
     ret = drm_->DestroyPropertyBlob(mode_.old_blob_id);
     if (ret) {
       ALOGE("Failed to destroy old mode property blob %lld/%d",
@@ -862,7 +869,7 @@
   int ret = status;
 
   if (!ret)
-    ret = CommitFrame(composition.get());
+    ret = CommitFrame(composition.get(), false);
 
   if (ret) {
     ALOGE("Composite failed for display %d", display_);

drmdisplaycompositor.h

diff --git a/drmdisplaycompositor.h b/drmdisplaycompositor.h
index a1cff13..bc19f35 100644
--- a/drmdisplaycompositor.h
+++ b/drmdisplaycompositor.h
@@ -142,7 +142,7 @@
   int ApplySquash(DrmDisplayComposition *display_comp);
   int ApplyPreComposite(DrmDisplayComposition *display_comp);
   int PrepareFrame(DrmDisplayComposition *display_comp);
-  int CommitFrame(DrmDisplayComposition *display_comp);
+  int CommitFrame(DrmDisplayComposition *display_comp, bool test_only);
   int ApplyDpms(DrmDisplayComposition *display_comp);
   int DisablePlanes(DrmDisplayComposition *display_comp);