hwc_vsync.cpp revision 513ddc2124abf90c63af41999201f0d2031af0c8 
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 "hwc_utils.h"
29#include "string.h"
30#include "external.h"
31
32namespace qhwc {
33
34#define HWC_VSYNC_THREAD_NAME "hwcVsyncThread"
35
36int hwc_vsync_control(hwc_context_t* ctx, int dpy, int enable)
37{
38    int ret = 0;
39    if(!ctx->vstate.fakevsync &&
40       ioctl(ctx->dpyAttr[dpy].fd, MSMFB_OVERLAY_VSYNC_CTRL,
41             &enable) < 0) {
42        ALOGE("%s: vsync control failed. Dpy=%d, enable=%d : %s",
43              __FUNCTION__, dpy, enable, strerror(errno));
44        ret = -errno;
45    }
46    return ret;
47}
48
49static void *vsync_loop(void *param)
50{
51    const char* vsync_timestamp_fb0 = "/sys/class/graphics/fb0/vsync_event";
52    const char* vsync_timestamp_fb1 = "/sys/class/graphics/fb1/vsync_event";
53    int dpy = HWC_DISPLAY_PRIMARY;
54
55    hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);
56
57    char thread_name[64] = HWC_VSYNC_THREAD_NAME;
58    prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
59    setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY +
60                android::PRIORITY_MORE_FAVORABLE);
61
62    const int MAX_DATA = 64;
63    static char vdata[MAX_DATA];
64
65    uint64_t cur_timestamp=0;
66    ssize_t len = -1;
67    int fd_timestamp = -1;
68    int ret = 0;
69    bool fb1_vsync = false;
70    bool logvsync = false;
71
72    char property[PROPERTY_VALUE_MAX];
73    if(property_get("debug.hwc.fakevsync", property, NULL) > 0) {
74        if(atoi(property) == 1)
75            ctx->vstate.fakevsync = true;
76    }
77
78    if(property_get("debug.hwc.logvsync", property, 0) > 0) {
79        if(atoi(property) == 1)
80            logvsync = true;
81    }
82
83    /* Currently read vsync timestamp from drivers
84       e.g. VSYNC=41800875994
85       */
86    fd_timestamp = open(vsync_timestamp_fb0, O_RDONLY);
87    if (fd_timestamp < 0) {
88        // Make sure fb device is opened before starting this thread so this
89        // never happens.
90        ALOGE ("FATAL:%s:not able to open file:%s, %s",  __FUNCTION__,
91               (fb1_vsync) ? vsync_timestamp_fb1 : vsync_timestamp_fb0,
92               strerror(errno));
93        ctx->vstate.fakevsync = true;
94    }
95
96    do {
97        if (LIKELY(!ctx->vstate.fakevsync)) {
98            len = pread(fd_timestamp, vdata, MAX_DATA, 0);
99            if (len < 0) {
100                // If the read was just interrupted - it is not a fatal error
101                // In either case, just continue.
102                if (errno != EAGAIN &&
103                    errno != EINTR  &&
104                    errno != EBUSY) {
105                    ALOGE ("FATAL:%s:not able to read file:%s, %s",
106                           __FUNCTION__,
107                           vsync_timestamp_fb0, strerror(errno));
108                }
109                continue;
110            }
111            // extract timestamp
112            const char *str = vdata;
113            if (!strncmp(str, "VSYNC=", strlen("VSYNC="))) {
114                cur_timestamp = strtoull(str + strlen("VSYNC="), NULL, 0);
115            }
116        } else {
117            usleep(16666);
118            cur_timestamp = systemTime();
119        }
120        // send timestamp to HAL
121        if(ctx->vstate.enable) {
122            ALOGD_IF (logvsync, "%s: timestamp %llu sent to HWC for %s",
123                      __FUNCTION__, cur_timestamp, "fb0");
124            ctx->proc->vsync(ctx->proc, dpy, cur_timestamp);
125        }
126
127    } while (true);
128    if(fd_timestamp >= 0)
129        close (fd_timestamp);
130
131    return NULL;
132}
133
134void init_vsync_thread(hwc_context_t* ctx)
135{
136    int ret;
137    pthread_t vsync_thread;
138    ALOGI("Initializing VSYNC Thread");
139    ret = pthread_create(&vsync_thread, NULL, vsync_loop, (void*) ctx);
140    if (ret) {
141        ALOGE("%s: failed to create %s: %s", __FUNCTION__,
142              HWC_VSYNC_THREAD_NAME, strerror(ret));
143    }
144}
145
146}; //namespace
147