1 files changed, 119 insertions, 5 deletions

diff --git a/libsuspend/autosuspend_earlysuspend.c b/libsuspend/autosuspend_earlysuspend.c
index 2c2aa36..1df8c6a 100644
--- a/libsuspend/autosuspend_earlysuspend.c
+++ b/libsuspend/autosuspend_earlysuspend.c
@@ -16,6 +16,8 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <pthread.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <string.h>
 #include <sys/types.h>
@@ -31,11 +33,75 @@
 #define EARLYSUSPEND_WAIT_FOR_FB_SLEEP "/sys/power/wait_for_fb_sleep"
 #define EARLYSUSPEND_WAIT_FOR_FB_WAKE "/sys/power/wait_for_fb_wake"
 
-
 static int sPowerStatefd;
 static const char *pwr_state_mem = "mem";
 static const char *pwr_state_on = "on";
+static pthread_t earlysuspend_thread;
+static pthread_mutex_t earlysuspend_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t earlysuspend_cond = PTHREAD_COND_INITIALIZER;
+static bool wait_for_earlysuspend;
+static enum {
+    EARLYSUSPEND_ON,
+    EARLYSUSPEND_MEM,
+} earlysuspend_state = EARLYSUSPEND_ON;
+
+int wait_for_fb_wake(void)
+{
+    int err = 0;
+    char buf;
+    int fd = open(EARLYSUSPEND_WAIT_FOR_FB_WAKE, O_RDONLY, 0);
+    // if the file doesn't exist, the error will be caught in read() below
+    do {
+        err = read(fd, &buf, 1);
+    } while (err < 0 && errno == EINTR);
+    ALOGE_IF(err < 0,
+            "*** ANDROID_WAIT_FOR_FB_WAKE failed (%s)", strerror(errno));
+    close(fd);
+    return err < 0 ? err : 0;
+}
+
+static int wait_for_fb_sleep(void)
+{
+    int err = 0;
+    char buf;
+    int fd = open(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, O_RDONLY, 0);
+    // if the file doesn't exist, the error will be caught in read() below
+    do {
+        err = read(fd, &buf, 1);
+    } while (err < 0 && errno == EINTR);
+    ALOGE_IF(err < 0,
+            "*** ANDROID_WAIT_FOR_FB_SLEEP failed (%s)", strerror(errno));
+    close(fd);
+    return err < 0 ? err : 0;
+}
+
+static void *earlysuspend_thread_func(void *arg)
+{
+    char buf[80];
+    char wakeup_count[20];
+    int wakeup_count_len;
+    int ret;
 
+    while (1) {
+        if (wait_for_fb_sleep()) {
+            ALOGE("Failed reading wait_for_fb_sleep, exiting earlysuspend thread\n");
+            return NULL;
+        }
+        pthread_mutex_lock(&earlysuspend_mutex);
+        earlysuspend_state = EARLYSUSPEND_MEM;
+        pthread_cond_signal(&earlysuspend_cond);
+        pthread_mutex_unlock(&earlysuspend_mutex);
+
+        if (wait_for_fb_wake()) {
+            ALOGE("Failed reading wait_for_fb_wake, exiting earlysuspend thread\n");
+            return NULL;
+        }
+        pthread_mutex_lock(&earlysuspend_mutex);
+        earlysuspend_state = EARLYSUSPEND_ON;
+        pthread_cond_signal(&earlysuspend_cond);
+        pthread_mutex_unlock(&earlysuspend_mutex);
+    }
+}
 static int autosuspend_earlysuspend_enable(void)
 {
     char buf[80];
@@ -50,6 +116,14 @@ static int autosuspend_earlysuspend_enable(void)
         goto err;
     }
 
+    if (wait_for_earlysuspend) {
+        pthread_mutex_lock(&earlysuspend_mutex);
+        while (earlysuspend_state != EARLYSUSPEND_MEM) {
+            pthread_cond_wait(&earlysuspend_cond, &earlysuspend_mutex);
+        }
+        pthread_mutex_unlock(&earlysuspend_mutex);
+    }
+
     ALOGV("autosuspend_earlysuspend_enable done\n");
 
     return 0;
@@ -72,6 +146,14 @@ static int autosuspend_earlysuspend_disable(void)
         goto err;
     }
 
+    if (wait_for_earlysuspend) {
+        pthread_mutex_lock(&earlysuspend_mutex);
+        while (earlysuspend_state != EARLYSUSPEND_ON) {
+            pthread_cond_wait(&earlysuspend_cond, &earlysuspend_mutex);
+        }
+        pthread_mutex_unlock(&earlysuspend_mutex);
+    }
+
     ALOGV("autosuspend_earlysuspend_disable done\n");
 
     return 0;
@@ -85,29 +167,61 @@ struct autosuspend_ops autosuspend_earlysuspend_ops = {
         .disable = autosuspend_earlysuspend_disable,
 };
 
-struct autosuspend_ops *autosuspend_earlysuspend_init(void)
+void start_earlysuspend_thread(void)
 {
     char buf[80];
     int ret;
 
     ret = access(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, F_OK);
     if (ret < 0) {
-        return NULL;
+        return;
     }
 
     ret = access(EARLYSUSPEND_WAIT_FOR_FB_WAKE, F_OK);
     if (ret < 0) {
-        return NULL;
+        return;
     }
 
+    wait_for_fb_wake();
+
+    ALOGI("Starting early suspend unblocker thread\n");
+    ret = pthread_create(&earlysuspend_thread, NULL, earlysuspend_thread_func, NULL);
+    if (ret) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error creating thread: %s\n", buf);
+        return;
+    }
+
+    wait_for_earlysuspend = true;
+}
+
+struct autosuspend_ops *autosuspend_earlysuspend_init(void)
+{
+    char buf[80];
+    int ret;
+
     sPowerStatefd = open(EARLYSUSPEND_SYS_POWER_STATE, O_RDWR);
 
     if (sPowerStatefd < 0) {
         strerror_r(errno, buf, sizeof(buf));
-        ALOGE("Error opening %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
+        ALOGW("Error opening %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
         return NULL;
     }
 
+    ret = write(sPowerStatefd, "on", 2);
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGW("Error writing 'on' to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
+        goto err_write;
+    }
+
     ALOGI("Selected early suspend\n");
+
+    start_earlysuspend_thread();
+
     return &autosuspend_earlysuspend_ops;
+
+err_write:
+    close(sPowerStatefd);
+    return NULL;
 }