commit 5983318f173039d813d2a7c7104cd574d844aadf
author Drew Davenport <ddavenport@google.com> Fri Dec 13 10:02:15 2024 -0700
committer Drew Davenport <ddavenport@google.com> Mon Dec 16 17:01:49 2024 -0700
tree 3aa1a255deeaa573d6dee349c0ff10a597b91be9
parent 0bc3df0be269a8d16e0e39c9cfae3068343ea0c9

drm_hwcomposer: Set vsync period for vsync thread

Make HwcDisplay set the VsyncWorker's vsync_period whenever it changes,
rather than having VsyncWorker query the vsync_period from HwcDisplay.

Doing so prevents the VsyncWorker thread from needing to acquire the
global lock to read HwcDisplay's state.

The original change called GetVsyncPeriod, which checks the vsync period
for the mode that is currently committed to the kernel based on
HwcDisplay::configs_.active_config_id, so call
VsyncWorker::SetVsyncPeriod whenever active_config_id is set.

Change-Id: Ie301c47e2496748117db8cca8a6ee9691e723c74
Signed-off-by: Drew Davenport <ddavenport@google.com>

hwc2_device/HwcDisplay.cpp

diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index 0503f39..6b676c2 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp
@@ -232,6 +232,8 @@
   ALOGV("Blocking config succeeded.");
   configs_.active_config_id = config;
   staged_mode_config_id_.reset();
+  vsync_worker_->SetVsyncPeriodNs(new_config->mode.GetVSyncPeriodNs());
+  // set new vsync period
   return ConfigError::kNone;
 }
 
@@ -329,11 +331,6 @@
               vsync_worker_->VSyncControl(false);
             }
           },
-      .get_vperiod_ns = [this]() -> uint32_t {
-        uint32_t outVsyncPeriod = 0;
-        GetDisplayVsyncPeriod(&outVsyncPeriod);
-        return outVsyncPeriod;
-      },
   };
 
   if (type_ != HWC2::DisplayType::Virtual) {
@@ -698,6 +695,7 @@
                      .bottom = int(staged_config->mode.GetRawMode().vdisplay)});
 
     configs_.active_config_id = staged_mode_config_id_.value();
+    vsync_worker_->SetVsyncPeriodNs(staged_config->mode.GetVSyncPeriodNs());
 
     a_args.display_mode = staged_config->mode;
     if (!a_args.test_only) {