1 /*
2 * Copyright (C) 2015 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 "hwc-vsync-worker"
18
19 #include "drmresources.h"
20 #include "vsyncworker.h"
21 #include "worker.h"
22
23 #include <map>
24 #include <stdlib.h>
25 #include <time.h>
26 #include <xf86drm.h>
27 #include <xf86drmMode.h>
28
29 #include <cutils/log.h>
30 #include <hardware/hardware.h>
31
32 namespace android {
33
VSyncWorker()34 VSyncWorker::VSyncWorker()
35 : Worker("vsync", HAL_PRIORITY_URGENT_DISPLAY),
36 drm_(NULL),
37 procs_(NULL),
38 display_(-1),
39 last_timestamp_(-1) {
40 }
41
~VSyncWorker()42 VSyncWorker::~VSyncWorker() {
43 }
44
Init(DrmResources * drm,int display)45 int VSyncWorker::Init(DrmResources *drm, int display) {
46 drm_ = drm;
47 display_ = display;
48
49 return InitWorker();
50 }
51
SetProcs(hwc_procs_t const * procs)52 int VSyncWorker::SetProcs(hwc_procs_t const *procs) {
53 int ret = Lock();
54 if (ret) {
55 ALOGE("Failed to lock vsync worker lock %d\n", ret);
56 return ret;
57 }
58
59 procs_ = procs;
60
61 ret = Unlock();
62 if (ret) {
63 ALOGE("Failed to unlock vsync worker lock %d\n", ret);
64 return ret;
65 }
66 return 0;
67 }
68
VSyncControl(bool enabled)69 int VSyncWorker::VSyncControl(bool enabled) {
70 int ret = Lock();
71 if (ret) {
72 ALOGE("Failed to lock vsync worker lock %d\n", ret);
73 return ret;
74 }
75
76 enabled_ = enabled;
77 last_timestamp_ = -1;
78 int signal_ret = SignalLocked();
79
80 ret = Unlock();
81 if (ret) {
82 ALOGE("Failed to unlock vsync worker lock %d\n", ret);
83 return ret;
84 }
85
86 return signal_ret;
87 }
88
89 /*
90 * Returns the timestamp of the next vsync in phase with last_timestamp_.
91 * For example:
92 * last_timestamp_ = 137
93 * frame_ns = 50
94 * current = 683
95 *
96 * ret = (50 * ((683 - 137)/50 + 1)) + 137
97 * ret = 687
98 *
99 * Thus, we must sleep until timestamp 687 to maintain phase with the last
100 * timestamp.
101 */
GetPhasedVSync(int64_t frame_ns,int64_t current)102 int64_t VSyncWorker::GetPhasedVSync(int64_t frame_ns, int64_t current) {
103 if (last_timestamp_ < 0)
104 return current + frame_ns;
105
106 return frame_ns * ((current - last_timestamp_) / frame_ns + 1) +
107 last_timestamp_;
108 }
109
110 static const int64_t kOneSecondNs = 1 * 1000 * 1000 * 1000;
111
SyntheticWaitVBlank(int64_t * timestamp)112 int VSyncWorker::SyntheticWaitVBlank(int64_t *timestamp) {
113 struct timespec vsync;
114 int ret = clock_gettime(CLOCK_MONOTONIC, &vsync);
115
116 float refresh = 60.0f; // Default to 60Hz refresh rate
117 DrmConnector *conn = drm_->GetConnectorForDisplay(display_);
118 if (conn && conn->active_mode().v_refresh() != 0.0f)
119 refresh = conn->active_mode().v_refresh();
120 else
121 ALOGW("Vsync worker active with conn=%p refresh=%f\n", conn,
122 conn ? conn->active_mode().v_refresh() : 0.0f);
123
124 int64_t phased_timestamp = GetPhasedVSync(
125 kOneSecondNs / refresh, vsync.tv_sec * kOneSecondNs + vsync.tv_nsec);
126 vsync.tv_sec = phased_timestamp / kOneSecondNs;
127 vsync.tv_nsec = phased_timestamp - (vsync.tv_sec * kOneSecondNs);
128 do {
129 ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &vsync, NULL);
130 } while (ret == -1 && errno == EINTR);
131 if (ret)
132 return ret;
133
134 *timestamp = (int64_t)vsync.tv_sec * kOneSecondNs + (int64_t)vsync.tv_nsec;
135 return 0;
136 }
137
Routine()138 void VSyncWorker::Routine() {
139 int ret = Lock();
140 if (ret) {
141 ALOGE("Failed to lock worker %d", ret);
142 return;
143 }
144
145 if (!enabled_) {
146 ret = WaitForSignalOrExitLocked();
147 if (ret == -EINTR) {
148 return;
149 }
150 }
151
152 bool enabled = enabled_;
153 int display = display_;
154 hwc_procs_t const *procs = procs_;
155
156 ret = Unlock();
157 if (ret) {
158 ALOGE("Failed to unlock worker %d", ret);
159 }
160
161 if (!enabled)
162 return;
163
164 DrmCrtc *crtc = drm_->GetCrtcForDisplay(display);
165 if (!crtc) {
166 ALOGE("Failed to get crtc for display");
167 return;
168 }
169 uint32_t high_crtc = (crtc->pipe() << DRM_VBLANK_HIGH_CRTC_SHIFT);
170
171 drmVBlank vblank;
172 memset(&vblank, 0, sizeof(vblank));
173 vblank.request.type = (drmVBlankSeqType)(
174 DRM_VBLANK_RELATIVE | (high_crtc & DRM_VBLANK_HIGH_CRTC_MASK));
175 vblank.request.sequence = 1;
176
177 int64_t timestamp;
178 ret = drmWaitVBlank(drm_->fd(), &vblank);
179 if (ret == -EINTR) {
180 return;
181 } else if (ret) {
182 ret = SyntheticWaitVBlank(×tamp);
183 if (ret)
184 return;
185 } else {
186 timestamp = (int64_t)vblank.reply.tval_sec * kOneSecondNs +
187 (int64_t)vblank.reply.tval_usec * 1000;
188 }
189
190 /*
191 * There's a race here where a change in procs_ will not take effect until
192 * the next subsequent requested vsync. This is unavoidable since we can't
193 * call the vsync hook while holding the thread lock.
194 *
195 * We could shorten the race window by caching procs_ right before calling
196 * the hook. However, in practice, procs_ is only updated once, so it's not
197 * worth the overhead.
198 */
199 if (procs && procs->vsync)
200 procs->vsync(procs, display, timestamp);
201 last_timestamp_ = timestamp;
202 }
203 }
204