Check timer version for read-block workaround

Check the timer protocl version whether to use poll for a workaround
of read-block problems.

diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c
index 379315f35c5a1047a2804a55dae938089e57cc42..c3f27ac9e3a7d5d2afded0375d8dbd3f9588454b 100644 (file)
--- a/src/pcm/pcm_direct.c
+++ b/src/pcm/pcm_direct.c
@@ -419,18 +419,26 @@ int snd_pcm_direct_async(snd_pcm_t *pcm, int sig, pid_t pid)
 /* empty the timer read queue */
 void snd_pcm_direct_clear_timer_queue(snd_pcm_direct_t *dmix)
 {
-       struct pollfd fds[4];
-       int fdn = snd_timer_poll_descriptors(dmix->timer, fds, 4);
-
-       while (poll(fds, fdn, 0) > 0) {
-               /* rbuf might be overwriten by multiple plugins */
-               /* we don't need the value */
+       if (dmix->timer_need_poll) {
+               while (poll(&dmix->timer_fd, 1, 0) > 0) {
+                       /* we don't need the value */
+                       if (dmix->tread) {
+                               snd_timer_tread_t rbuf;
+                               snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf));
+                       } else {
+                               snd_timer_read_t rbuf;
+                               snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf));
+                       }
+               }
+       } else {
                if (dmix->tread) {
                        snd_timer_tread_t rbuf;
-                       snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf));
+                       while (snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf)) > 0)
+                               ;
                } else {
                        snd_timer_read_t rbuf;
-                       snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf));
+                       while (snd_timer_read(dmix->timer, &rbuf, sizeof(rbuf)) > 0)
+                               ;
                }
        }
 }
@@ -859,10 +867,10 @@ int snd_pcm_direct_initialize_poll_fd(snd_pcm_direct_t *dmix)
        snd_pcm_info_t *info;
        snd_timer_params_t *params;
        char name[128];
-       struct pollfd fd;
        int capture = dmix->type == SND_PCM_TYPE_DSNOOP ? 1 : 0;
        
        dmix->tread = 0;
+       dmix->timer_need_poll = 0;
        snd_pcm_info_alloca(&info);
        snd_timer_params_alloca(&params);
        ret = snd_pcm_info(dmix->spcm, info);
@@ -886,8 +894,8 @@ int snd_pcm_direct_initialize_poll_fd(snd_pcm_direct_t *dmix)
                SNDERR("unable to use timer with fd more than one!!!", name);
                return ret;
        }
-       snd_timer_poll_descriptors(dmix->timer, &fd, 1);
-       dmix->poll_fd = fd.fd;
+       snd_timer_poll_descriptors(dmix->timer, &dmix->timer_fd, 1);
+       dmix->poll_fd = dmix->timer_fd.fd;
 
        /*
         * A hack to avoid Oops in the older kernel
@@ -902,6 +910,12 @@ int snd_pcm_direct_initialize_poll_fd(snd_pcm_direct_t *dmix)
                        if (ioctl(dmix->poll_fd, SNDRV_TIMER_IOCTL_TREAD, &dmix->tread) < 0)
                                dmix->tread = 0;
                }
+               /* In older versions, check via poll before read() is needed
+                * because of the confliction between TIMER_START and
+                * FIONBIO ioctls.
+                */
+               if (ver < SNDRV_PROTOCOL_VERSION(2, 0, 4))
+                       dmix->timer_need_poll = 1;
        }
 
        snd_timer_params_set_auto_start(params, 1);

diff --git a/src/pcm/pcm_direct.h b/src/pcm/pcm_direct.h
index 26de01877aa25c2bf1e03d8213898f40a218fcd1..675bca4146debd0966abf1bdc24cbdb9b8772050 100644 (file)
--- a/src/pcm/pcm_direct.h
+++ b/src/pcm/pcm_direct.h
@@ -95,8 +95,10 @@ struct snd_pcm_direct {
        int server, client;
        int comm_fd;                    /* communication file descriptor (socket) */
        int hw_fd;                      /* hardware file descriptor */
+       struct pollfd timer_fd;
        int poll_fd;
        int tread;
+       int timer_need_poll;
        int server_fd;
        pid_t server_pid;
        snd_timer_t *timer;             /* timer used as poll_fd */