1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #define LOG_TAG "drmhwc" 18 19 #include "UEventListener.h" 20 21 #include <thread> 22 23 #include "utils/log.h" 24 25 namespace android { 26 StopThread()27void UEventListener::StopThread() { 28 uevent_->Stop(); 29 } 30 CreateInstance()31auto UEventListener::CreateInstance() -> std::shared_ptr<UEventListener> { 32 auto uel = std::shared_ptr<UEventListener>(new UEventListener()); 33 34 uel->uevent_ = UEvent::CreateInstance(); 35 if (!uel->uevent_) 36 return {}; 37 38 std::thread(&UEventListener::ThreadFn, uel.get(), uel).detach(); 39 40 return uel; 41 } 42 ThreadFn(const std::shared_ptr<UEventListener> & uel)43void UEventListener::ThreadFn(const std::shared_ptr<UEventListener> &uel) { 44 // TODO(nobody): Rework code to allow stopping the thread (low priority) 45 while (true) { 46 if (uel.use_count() == 1) 47 break; 48 49 auto uevent_str = uel->uevent_->ReadNext(); 50 51 if (!hotplug_handler_ || !uevent_str) 52 continue; 53 54 auto drm_event = uevent_str->find("DEVTYPE=drm_minor") != std::string::npos; 55 auto hotplug_event = uevent_str->find("HOTPLUG=1") != std::string::npos; 56 57 if (drm_event && hotplug_event) { 58 constexpr useconds_t kDelayAfterUeventUs = 200000; 59 /* We need some delay to ensure DrmConnector::UpdateModes() will query 60 * correct modes list, otherwise at least RPI4 board may report 0 modes */ 61 usleep(kDelayAfterUeventUs); 62 hotplug_handler_(); 63 } 64 } 65 66 ALOGI("UEvent thread exit"); 67 } 68 69 } // namespace android 70