hwc_vsync.cpp revision 6287ca3d8c0bc7bd6e18c729781ea1d03bb23034 
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
33namespace qhwc {
34
35#define HWC_VSYNC_THREAD_NAME "hwcVsyncThread"
36
37int hwc_vsync_control(hwc_context_t* ctx, int dpy, int enable)
38{
39    int ret = 0;
40    if(!ctx->vstate.fakevsync &&
41       ioctl(ctx->dpyAttr[dpy].fd, MSMFB_OVERLAY_VSYNC_CTRL,
42             &enable) < 0) {
43        ALOGE("%s: vsync control failed. Dpy=%d, enable=%d : %s",
44              __FUNCTION__, dpy, enable, strerror(errno));
45        ret = -errno;
46    }
47    return ret;
48}
49
50static void *vsync_loop(void *param)
51{
52    const char* vsync_timestamp_fb0 = "/sys/class/graphics/fb0/vsync_event";
53    const char* vsync_timestamp_fb1 = "/sys/class/graphics/fb1/vsync_event";
54    int dpy = HWC_DISPLAY_PRIMARY;
55
56    hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);
57
58    char thread_name[64] = HWC_VSYNC_THREAD_NAME;
59    prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
60    setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY +
61                android::PRIORITY_MORE_FAVORABLE);
62
63    const int MAX_DATA = 64;
64    static char vdata[MAX_DATA];
65    struct pollfd pfd;
66
67    uint64_t cur_timestamp=0;
68    ssize_t len = -1;
69    int fb0_fd = -1;
70    int ret = 0;
71    bool fb1_vsync = false;
72    bool logvsync = false;
73
74    char property[PROPERTY_VALUE_MAX];
75    if(property_get("debug.hwc.fakevsync", property, NULL) > 0) {
76        if(atoi(property) == 1)
77            ctx->vstate.fakevsync = true;
78    }
79
80    if(property_get("debug.hwc.logvsync", property, 0) > 0) {
81        if(atoi(property) == 1)
82            logvsync = true;
83    }
84
85    /* Currently read vsync timestamp from drivers
86       e.g. VSYNC=41800875994
87       */
88    fb0_fd = open(vsync_timestamp_fb0, O_RDONLY);
89    pfd.fd = fb0_fd;
90    pfd.events = POLLPRI | POLLERR;
91
92    if (fb0_fd < 0) {
93        // Make sure fb device is opened before starting this thread so this
94        // never happens.
95        ALOGE ("FATAL:%s:not able to open file:%s, %s",  __FUNCTION__,
96               (fb1_vsync) ? vsync_timestamp_fb1 : vsync_timestamp_fb0,
97               strerror(errno));
98        ctx->vstate.fakevsync = true;
99    }
100
101    do {
102        if (LIKELY(!ctx->vstate.fakevsync)) {
103            int err = poll(&pfd, 1, -1);
104            if(err > 0) {
105                if (pfd.revents & POLLPRI) {
106                    len = pread(fb0_fd, vdata, MAX_DATA, 0);
107                    if (UNLIKELY(len < 0)) {
108                        // If the read was just interrupted - it is not a fatal
109                        // error. Just continue in this case
110                        ALOGE ("FATAL:%s:not able to read file:%s, %s",
111                               __FUNCTION__,
112                               vsync_timestamp_fb0, strerror(errno));
113                        continue;
114                    }
115                    // extract timestamp
116                    const char *str = vdata;
117                    if (!strncmp(str, "VSYNC=", strlen("VSYNC="))) {
118                        cur_timestamp = strtoull(str + strlen("VSYNC="),
119                                                 NULL, 0);
120                    }
121                }
122            } else {
123                ALOGE("%s: vsync poll failed errno: %s", __FUNCTION__,
124                      strerror(errno));
125                continue;
126            }
127        } else {
128            usleep(16666);
129            cur_timestamp = systemTime();
130        }
131        // send timestamp to HAL
132        if(ctx->vstate.enable) {
133            ALOGD_IF (logvsync, "%s: timestamp %llu sent to HWC for %s",
134                      __FUNCTION__, cur_timestamp, "fb0");
135            ctx->proc->vsync(ctx->proc, dpy, cur_timestamp);
136        }
137
138    } while (true);
139    if(fb0_fd >= 0)
140        close (fb0_fd);
141
142    return NULL;
143}
144
145void init_vsync_thread(hwc_context_t* ctx)
146{
147    int ret;
148    pthread_t vsync_thread;
149    ALOGI("Initializing VSYNC Thread");
150    ret = pthread_create(&vsync_thread, NULL, vsync_loop, (void*) ctx);
151    if (ret) {
152        ALOGE("%s: failed to create %s: %s", __FUNCTION__,
153              HWC_VSYNC_THREAD_NAME, strerror(ret));
154    }
155}
156
157}; //namespace
158