commit aa8ec5204dc019acab6b20b1830469c414439ee7
author Roman Stratiienko <roman.o.stratiienko@globallogic.com> Mon Jan 17 13:17:56 2022 +0200
committer Roman Stratiienko <roman.o.stratiienko@globallogic.com> Thu Jan 20 17:21:46 2022 +0200
tree 0f5179f58cbc99942756fd571dc01b17a3338667
parent 74923586982248de6c41dd45d0aee6a918365bc6

drm_hwcomposer: Configuring Composer HAL to use sequential IDs

Implement Google guidelines from [1]

1. The supported display config IDs are:

    id=1, 1080x1920 60hz
    id=2, 1080x1920 50hz

2. When a change of display configs is processed, the next set of config IDs
   are assigned starting from the next unused integer, shown as follows:

    id=3, 2160x3840 60hz
    id=4, 2160x3840 50hz
    id=5, 1080x1920 60hz
    id=6, 1080x1920 50hz

+ Don't update modes in GetDisplayConfigs() . Modes is now updated at init or
after every hotplug event.

[1]: https://source.android.com/devices/graphics/hotplug#configuring-composer-hal-sequential-ids
Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>

hwc2_device/HwcDisplayConfigs.cpp

diff --git a/hwc2_device/HwcDisplayConfigs.cpp b/hwc2_device/HwcDisplayConfigs.cpp
index d1a8d4c..e3d17a2 100644
--- a/hwc2_device/HwcDisplayConfigs.cpp
+++ b/hwc2_device/HwcDisplayConfigs.cpp
@@ -33,16 +33,16 @@
     return HWC2::Error::BadDisplay;
   }
 
-  hwc_configs.clear();
-  preferred_config_id = 0;
-  int preferred_config_group_id = 0;
-
   if (connector.modes().empty()) {
     ALOGE("No modes reported by KMS");
     return HWC2::Error::BadDisplay;
   }
 
-  int last_config_id = 1;
+  hwc_configs.clear();
+  preferred_config_id = 0;
+  int preferred_config_group_id = 0;
+
+  int first_config_id = last_config_id;
   int last_group_id = 1;
 
   /* Group modes */
@@ -87,7 +87,7 @@
   /* We must have preferred mode. Set first mode as preferred
    * in case KMS haven't reported anything. */
   if (preferred_config_id == 0) {
-    preferred_config_id = 1;
+    preferred_config_id = first_config_id;
     preferred_config_group_id = 1;
   }
 
@@ -142,8 +142,8 @@
    * otherwise android.graphics.cts.SetFrameRateTest CTS will fail
    */
   constexpr float kMinFpsDelta = 1.0;  // FPS
-  for (int m1 = 1; m1 < last_config_id; m1++) {
-    for (int m2 = 1; m2 < last_config_id; m2++) {
+  for (int m1 = first_config_id; m1 < last_config_id; m1++) {
+    for (int m2 = first_config_id; m2 < last_config_id; m2++) {
       if (m1 != m2 && hwc_configs[m1].group_id == hwc_configs[m2].group_id &&
           !hwc_configs[m1].disabled && !hwc_configs[m2].disabled &&
           fabsf(hwc_configs[m1].mode.v_refresh() -