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1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  * Copyright (C) 2012-2013, The Linux Foundation. All rights reserved.
4  *
5  * Not a Contribution, Apache license notifications and license are
6  * retained for attribution purposes only.
7 
8  * Licensed under the Apache License, Version 2.0 (the "License");
9  * you may not use this file except in compliance with the License.
10  * You may obtain a copy of the License at
11  *
12  *      http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20 
21 #include <cutils/properties.h>
22 #include <utils/Log.h>
23 #include <fcntl.h>
24 #include <sys/ioctl.h>
25 #include <linux/msm_mdp.h>
26 #include <sys/resource.h>
27 #include <sys/prctl.h>
28 #include <poll.h>
29 #include "hwc_utils.h"
30 #include "string.h"
31 #include "external.h"
32 
33 namespace qhwc {
34 
35 #define HWC_VSYNC_THREAD_NAME "hwcVsyncThread"
36 #define MAX_SYSFS_FILE_PATH             255
37 
hwc_vsync_control(hwc_context_t * ctx,int dpy,int enable)38 int hwc_vsync_control(hwc_context_t* ctx, int dpy, int enable)
39 {
40     int ret = 0;
41     if(!ctx->vstate.fakevsync &&
42        ioctl(ctx->dpyAttr[dpy].fd, MSMFB_OVERLAY_VSYNC_CTRL,
43              &enable) < 0) {
44         ALOGE("%s: vsync control failed. Dpy=%d, enable=%d : %s",
45               __FUNCTION__, dpy, enable, strerror(errno));
46         ret = -errno;
47     }
48     return ret;
49 }
50 
vsync_loop(void * param)51 static void *vsync_loop(void *param)
52 {
53     hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);
54 
55     char thread_name[64] = HWC_VSYNC_THREAD_NAME;
56     prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
57     setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY +
58                 android::PRIORITY_MORE_FAVORABLE);
59 
60     const int MAX_DATA = 64;
61     char vdata[MAX_DATA];
62     bool logvsync = false;
63 
64     struct pollfd pfd[2];
65     int fb_fd[2];
66     uint64_t timestamp[2];
67     int num_displays;
68 
69     char property[PROPERTY_VALUE_MAX];
70     if(property_get("debug.hwc.fakevsync", property, NULL) > 0) {
71         if(atoi(property) == 1)
72             ctx->vstate.fakevsync = true;
73     }
74 
75     if(property_get("debug.hwc.logvsync", property, 0) > 0) {
76         if(atoi(property) == 1)
77             logvsync = true;
78     }
79 
80     if (ctx->mExtDisplay->getHDMIIndex() > 0)
81         num_displays = 2;
82     else
83         num_displays = 1;
84 
85     char vsync_node_path[MAX_SYSFS_FILE_PATH];
86     for (int dpy = HWC_DISPLAY_PRIMARY; dpy < num_displays; dpy++) {
87         snprintf(vsync_node_path, sizeof(vsync_node_path),
88                 "/sys/class/graphics/fb%d/vsync_event",
89                 dpy == HWC_DISPLAY_PRIMARY ? 0 :
90                 ctx->mExtDisplay->getHDMIIndex());
91         ALOGI("%s: Reading vsync for dpy=%d from %s", __FUNCTION__, dpy,
92                 vsync_node_path);
93         fb_fd[dpy] = open(vsync_node_path, O_RDONLY);
94 
95         if (fb_fd[dpy] < 0) {
96             // Make sure fb device is opened before starting this thread so this
97             // never happens.
98             ALOGE ("%s:not able to open vsync node for dpy=%d, %s",
99                     __FUNCTION__, dpy, strerror(errno));
100             if (dpy == HWC_DISPLAY_PRIMARY) {
101                 ctx->vstate.fakevsync = true;
102                 break;
103             }
104         }
105         // Read once from the fds to clear the first notify
106         pread(fb_fd[dpy], vdata , MAX_DATA, 0);
107 
108         pfd[dpy].fd = fb_fd[dpy];
109         if (pfd[dpy].fd >= 0)
110             pfd[dpy].events = POLLPRI | POLLERR;
111     }
112 
113     if (LIKELY(!ctx->vstate.fakevsync)) {
114         do {
115             int err = poll(pfd, num_displays, -1);
116             if(err > 0) {
117                 for (int dpy = HWC_DISPLAY_PRIMARY; dpy < num_displays; dpy++) {
118                     if (pfd[dpy].revents & POLLPRI) {
119                         int len = pread(pfd[dpy].fd, vdata, MAX_DATA, 0);
120                         if (UNLIKELY(len < 0)) {
121                             // If the read was just interrupted - it is not a
122                             // fatal error. Just continue in this case
123                             ALOGE ("%s: Unable to read vsync for dpy=%d : %s",
124                                     __FUNCTION__, dpy, strerror(errno));
125                             continue;
126                         }
127                         // extract timestamp
128                         if (!strncmp(vdata, "VSYNC=", strlen("VSYNC="))) {
129                             timestamp[dpy] = strtoull(vdata + strlen("VSYNC="),
130                                     NULL, 0);
131                         }
132                         // send timestamp to SurfaceFlinger
133                         ALOGD_IF (logvsync,
134                                 "%s: timestamp %llu sent to SF for dpy=%d",
135                                 __FUNCTION__, timestamp[dpy], dpy);
136                         ctx->proc->vsync(ctx->proc, dpy, timestamp[dpy]);
137                     }
138                 }
139 
140             } else {
141                 ALOGE("%s: vsync poll failed errno: %s", __FUNCTION__,
142                         strerror(errno));
143                 continue;
144             }
145         } while (true);
146 
147     } else {
148 
149         //Fake vsync is used only when set explicitly through a property or when
150         //the vsync timestamp node cannot be opened at bootup. There is no
151         //fallback to fake vsync from the true vsync loop, ever, as the
152         //condition can easily escape detection.
153         //Also, fake vsync is delivered only for the primary display.
154         do {
155             usleep(16666);
156             timestamp[HWC_DISPLAY_PRIMARY] = systemTime();
157             ctx->proc->vsync(ctx->proc, HWC_DISPLAY_PRIMARY,
158                     timestamp[HWC_DISPLAY_PRIMARY]);
159 
160         } while (true);
161     }
162 
163     for (int dpy = HWC_DISPLAY_PRIMARY; dpy <= HWC_DISPLAY_EXTERNAL; dpy++ ) {
164         if(fb_fd[dpy] >= 0)
165             close (fb_fd[dpy]);
166     }
167 
168     return NULL;
169 }
170 
init_vsync_thread(hwc_context_t * ctx)171 void init_vsync_thread(hwc_context_t* ctx)
172 {
173     int ret;
174     pthread_t vsync_thread;
175     ALOGI("Initializing VSYNC Thread");
176     ret = pthread_create(&vsync_thread, NULL, vsync_loop, (void*) ctx);
177     if (ret) {
178         ALOGE("%s: failed to create %s: %s", __FUNCTION__,
179               HWC_VSYNC_THREAD_NAME, strerror(ret));
180     }
181 }
182 
183 }; //namespace
184