pcm: Return the consistent error code for unexpected PCM states

Some PCM functions have the sanity check of the expected PCM states,
and most of them return -EBADFD if the current state doesn't match.
This is bad for some programs like aplay that expect the function
returning a proper code corresponding to the state, e.g. -ESTRPIPE for
the suspend.

This patch is an attempt to address such inconsistencies.  The sanity
checker bad_pcm_state() now returns the error code instead of bool, so
that the caller can pass the returned code as is.  And it calls a new
helper, pcm_state_to_error(), for obtaining the error code to certain
known PCM error state.

While we're at it, use the new pcm_state_to_error() for simplifying
the existing code to retrieve the error code, too.

Tested-by: Mirza Krak <mirza.krak@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index e9ebf38..69d7d66 100644 (file)
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -657,6 +657,21 @@ playback devices.
 #include "pcm_local.h"
 
 #ifndef DOC_HIDDEN
+/* return specific error codes for known bad PCM states */
+static int pcm_state_to_error(snd_pcm_state_t state)
+{
+       switch (state) {
+       case SND_PCM_STATE_XRUN:
+               return -EPIPE;
+       case SND_PCM_STATE_SUSPENDED:
+               return -ESTRPIPE;
+       case SND_PCM_STATE_DISCONNECTED:
+               return -ENODEV;
+       default:
+               return 0;
+       }
+}
+
 #define P_STATE(x)     (1U << SND_PCM_STATE_ ## x)
 #define P_STATE_RUNNABLE (P_STATE(PREPARED) | \
                          P_STATE(RUNNING) | \
@@ -667,9 +682,18 @@ playback devices.
 /* check whether the PCM is in the unexpected state */
 static int bad_pcm_state(snd_pcm_t *pcm, unsigned int supported_states)
 {
+       snd_pcm_state_t state;
+       int err;
+
        if (pcm->own_state_check)
                return 0; /* don't care, the plugin checks by itself */
-       return !(supported_states & (1U << snd_pcm_state(pcm)));
+       state = snd_pcm_state(pcm);
+       if (supported_states & (1U << state))
+               return 0; /* OK */
+       err = pcm_state_to_error(state);
+       if (err < 0)
+               return err;
+       return -EBADFD;
 }
 #endif
 
@@ -1143,8 +1167,9 @@ int snd_pcm_prepare(snd_pcm_t *pcm)
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, ~P_STATE(DISCONNECTED)))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, ~P_STATE(DISCONNECTED));
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        err = pcm->fast_ops->prepare(pcm->fast_op_arg);
        snd_pcm_unlock(pcm);
@@ -1191,8 +1216,9 @@ int snd_pcm_start(snd_pcm_t *pcm)
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE(PREPARED)))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE(PREPARED));
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        err = __snd_pcm_start(pcm);
        snd_pcm_unlock(pcm);
@@ -1221,9 +1247,10 @@ int snd_pcm_drop(snd_pcm_t *pcm)
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE | P_STATE(SETUP) |
-                            P_STATE(SUSPENDED)))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE | P_STATE(SETUP) |
+                           P_STATE(SUSPENDED));
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        err = pcm->fast_ops->drop(pcm->fast_op_arg);
        snd_pcm_unlock(pcm);
@@ -1247,13 +1274,16 @@ int snd_pcm_drop(snd_pcm_t *pcm)
  */
 int snd_pcm_drain(snd_pcm_t *pcm)
 {
+       int err;
+
        assert(pcm);
        if (CHECK_SANITY(! pcm->setup)) {
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        /* lock handled in the callback */
        return pcm->fast_ops->drain(pcm->fast_op_arg);
 }
@@ -1279,8 +1309,9 @@ int snd_pcm_pause(snd_pcm_t *pcm, int enable)
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        err = pcm->fast_ops->pause(pcm->fast_op_arg, enable);
        snd_pcm_unlock(pcm);
@@ -1301,14 +1332,16 @@ int snd_pcm_pause(snd_pcm_t *pcm, int enable)
 snd_pcm_sframes_t snd_pcm_rewindable(snd_pcm_t *pcm)
 {
        snd_pcm_sframes_t result;
+       int err;
 
        assert(pcm);
        if (CHECK_SANITY(! pcm->setup)) {
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        result = pcm->fast_ops->rewindable(pcm->fast_op_arg);
        snd_pcm_unlock(pcm);
@@ -1327,6 +1360,7 @@ snd_pcm_sframes_t snd_pcm_rewindable(snd_pcm_t *pcm)
 snd_pcm_sframes_t snd_pcm_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
 {
        snd_pcm_sframes_t result;
+       int err;
 
        assert(pcm);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1335,8 +1369,9 @@ snd_pcm_sframes_t snd_pcm_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
        }
        if (frames == 0)
                return 0;
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        result = pcm->fast_ops->rewind(pcm->fast_op_arg, frames);
        snd_pcm_unlock(pcm);
@@ -1357,14 +1392,16 @@ snd_pcm_sframes_t snd_pcm_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
 snd_pcm_sframes_t snd_pcm_forwardable(snd_pcm_t *pcm)
 {
        snd_pcm_sframes_t result;
+       int err;
 
        assert(pcm);
        if (CHECK_SANITY(! pcm->setup)) {
                SNDMSG("PCM not set up");
                return -EIO;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        result = pcm->fast_ops->forwardable(pcm->fast_op_arg);
        snd_pcm_unlock(pcm);
@@ -1387,6 +1424,7 @@ snd_pcm_sframes_t snd_pcm_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
 #endif
 {
        snd_pcm_sframes_t result;
+       int err;
 
        assert(pcm);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1395,8 +1433,9 @@ snd_pcm_sframes_t snd_pcm_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
        }
        if (frames == 0)
                return 0;
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        result = pcm->fast_ops->forward(pcm->fast_op_arg, frames);
        snd_pcm_unlock(pcm);
@@ -1425,6 +1464,8 @@ use_default_symbol_version(__snd_pcm_forward, snd_pcm_forward, ALSA_0.9.0rc8);
  */ 
 snd_pcm_sframes_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size)
 {
+       int err;
+
        assert(pcm);
        assert(size == 0 || buffer);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1435,8 +1476,9 @@ snd_pcm_sframes_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_ufr
                SNDMSG("invalid access type %s", snd_pcm_access_name(pcm->access));
                return -EINVAL;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        return _snd_pcm_writei(pcm, buffer, size);
 }
 
@@ -1461,6 +1503,8 @@ snd_pcm_sframes_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_ufr
  */ 
 snd_pcm_sframes_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t size)
 {
+       int err;
+
        assert(pcm);
        assert(size == 0 || bufs);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1471,8 +1515,9 @@ snd_pcm_sframes_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t
                SNDMSG("invalid access type %s", snd_pcm_access_name(pcm->access));
                return -EINVAL;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        return _snd_pcm_writen(pcm, bufs, size);
 }
 
@@ -1497,6 +1542,8 @@ snd_pcm_sframes_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t
  */ 
 snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
 {
+       int err;
+
        assert(pcm);
        assert(size == 0 || buffer);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1507,8 +1554,9 @@ snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t
                SNDMSG("invalid access type %s", snd_pcm_access_name(pcm->access));
                return -EINVAL;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        return _snd_pcm_readi(pcm, buffer, size);
 }
 
@@ -1533,6 +1581,8 @@ snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t
  */ 
 snd_pcm_sframes_t snd_pcm_readn(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t size)
 {
+       int err;
+
        assert(pcm);
        assert(size == 0 || bufs);
        if (CHECK_SANITY(! pcm->setup)) {
@@ -1543,8 +1593,9 @@ snd_pcm_sframes_t snd_pcm_readn(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t s
                SNDMSG("invalid access type %s", snd_pcm_access_name(pcm->access));
                return -EINVAL;
        }
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        return _snd_pcm_readn(pcm, bufs, size);
 }
 
@@ -2695,18 +2746,12 @@ int snd_pcm_wait(snd_pcm_t *pcm, int timeout)
 /* locked version */
 int __snd_pcm_wait_in_lock(snd_pcm_t *pcm, int timeout)
 {
+       int err;
+
        if (!snd_pcm_may_wait_for_avail_min(pcm, snd_pcm_mmap_avail(pcm))) {
                /* check more precisely */
-               switch (__snd_pcm_state(pcm)) {
-               case SND_PCM_STATE_XRUN:
-                       return -EPIPE;
-               case SND_PCM_STATE_SUSPENDED:
-                       return -ESTRPIPE;
-               case SND_PCM_STATE_DISCONNECTED:
-                       return -ENODEV;
-               default:
-                       return 1;
-               }
+               err = pcm_state_to_error(__snd_pcm_state(pcm));
+               return err < 0 ? err : 1;
        }
        return snd_pcm_wait_nocheck(pcm, timeout);
 }
@@ -2753,16 +2798,8 @@ int snd_pcm_wait_nocheck(snd_pcm_t *pcm, int timeout)
                        return err;
                if (revents & (POLLERR | POLLNVAL)) {
                        /* check more precisely */
-                       switch (__snd_pcm_state(pcm)) {
-                       case SND_PCM_STATE_XRUN:
-                               return -EPIPE;
-                       case SND_PCM_STATE_SUSPENDED:
-                               return -ESTRPIPE;
-                       case SND_PCM_STATE_DISCONNECTED:
-                               return -ENODEV;
-                       default:
-                               return -EIO;
-                       }
+                       err = pcm_state_to_error(__snd_pcm_state(pcm));
+                       return err < 0 ? err : -EIO;
                }
        } while (!(revents & (POLLIN | POLLOUT)));
 #if 0 /* very useful code to test poll related problems */
@@ -7010,8 +7047,9 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
 {
        int err;
 
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        err = __snd_pcm_mmap_begin(pcm, areas, offset, frames);
        snd_pcm_unlock(pcm);
@@ -7106,9 +7144,11 @@ snd_pcm_sframes_t snd_pcm_mmap_commit(snd_pcm_t *pcm,
                                      snd_pcm_uframes_t frames)
 {
        snd_pcm_sframes_t result;
+       int err;
 
-       if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
-               return -EBADFD;
+       err = bad_pcm_state(pcm, P_STATE_RUNNABLE);
+       if (err < 0)
+               return err;
        snd_pcm_lock(pcm);
        result = __snd_pcm_mmap_commit(pcm, offset, frames);
        snd_pcm_unlock(pcm);
@@ -7204,17 +7244,10 @@ snd_pcm_sframes_t snd_pcm_read_areas(snd_pcm_t *pcm, const snd_pcm_channel_area_
                case SND_PCM_STATE_DRAINING:
                case SND_PCM_STATE_PAUSED:
                        break;
-               case SND_PCM_STATE_XRUN:
-                       err = -EPIPE;
-                       goto _end;
-               case SND_PCM_STATE_SUSPENDED:
-                       err = -ESTRPIPE;
-                       goto _end;
-               case SND_PCM_STATE_DISCONNECTED:
-                       err = -ENODEV;
-                       goto _end;
                default:
-                       err = -EBADFD;
+                       err = pcm_state_to_error(state);
+                       if (!err)
+                               err = -EBADFD;
                        goto _end;
                }
                avail = __snd_pcm_avail_update(pcm);
@@ -7280,17 +7313,10 @@ snd_pcm_sframes_t snd_pcm_write_areas(snd_pcm_t *pcm, const snd_pcm_channel_area
                        if (err < 0)
                                goto _end;
                        break;
-               case SND_PCM_STATE_XRUN:
-                       err = -EPIPE;
-                       goto _end;
-               case SND_PCM_STATE_SUSPENDED:
-                       err = -ESTRPIPE;
-                       goto _end;
-               case SND_PCM_STATE_DISCONNECTED:
-                       err = -ENODEV;
-                       goto _end;
                default:
-                       err = -EBADFD;
+                       err = pcm_state_to_error(state);
+                       if (!err)
+                               err = -EBADFD;
                        goto _end;
                }
                avail = __snd_pcm_avail_update(pcm);