axfer: code refactoring for a helper function to wait for avail buffer space

This commit applies code refactoring for waiting PCM event queued
per period of PCM buffer in copying operation for IRQ-based scheduling
model.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/axfer/xfer-libasound-irq-rw.c b/axfer/xfer-libasound-irq-rw.c
index cf4155f..184b85a 100644 (file)
--- a/axfer/xfer-libasound-irq-rw.c
+++ b/axfer/xfer-libasound-irq-rw.c
@@ -19,6 +19,32 @@ struct rw_closure {
        struct frame_cache cache;
 };
 
+static int wait_for_avail(struct libasound_state *state)
+{
+       unsigned short revents;
+       unsigned short event;
+       int err;
+
+       // Wait for hardware IRQ when no available space.
+       err = xfer_libasound_wait_event(state, -1, &revents);
+       if (err < 0)
+               return err;
+
+       // TODO: error reporting.
+       if (revents & POLLERR)
+               return -EIO;
+
+       if (snd_pcm_stream(state->handle) == SND_PCM_STREAM_CAPTURE)
+               event = POLLIN;
+       else
+               event = POLLOUT;
+
+       if (!(revents & event))
+               return -EAGAIN;
+
+       return 0;
+}
+
 static int read_frames(struct libasound_state *state, unsigned int *frame_count,
                       unsigned int avail_count, struct mapper_context *mapper,
                       struct container_context *cntrs)
@@ -134,21 +160,9 @@ static int r_process_frames_nonblocking(struct libasound_state *state,
        }
 
        if (state->use_waiter) {
-               unsigned short revents;
-
-               // Wait for hardware IRQ when no available space.
-               err = xfer_libasound_wait_event(state, -1, &revents);
+               err = wait_for_avail(state);
                if (err < 0)
                        goto error;
-               if (revents & POLLERR) {
-                       // TODO: error reporting.
-                       err = -EIO;
-                       goto error;
-               }
-               if (!(revents & POLLIN)) {
-                       err = -EAGAIN;
-                       goto error;
-               }
        }
 
        // Check available space on the buffer.
@@ -300,21 +314,9 @@ static int w_process_frames_nonblocking(struct libasound_state *state,
        int err;
 
        if (state->use_waiter) {
-               unsigned short revents;
-
-               // Wait for hardware IRQ when no left space.
-               err = xfer_libasound_wait_event(state, -1, &revents);
+               err = wait_for_avail(state);
                if (err < 0)
                        goto error;
-               if (revents & POLLERR) {
-                       // TODO: error reporting.
-                       err = -EIO;
-                       goto error;
-               }
-               if (!(revents & POLLOUT)) {
-                       err = -EAGAIN;
-                       goto error;
-               }
        }
 
        // Check available space on the buffer.