PCM: plug: Move fast_ops copy after slave configuration.

This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
The plug plugin copies the fast_ops structure and fast_op_arg from its
slave PCM on initialization and after inserting a new plugin. This works
unless the slave PCM is also an instance of the plug plugin because plug
can change its fast_ops structure during _snd_pcm_hw_params.

Instead of copying fast_ops in snd_pcm_plug_insert_plugins wait until
the end of snd_pcm_plug_hw_params when the slave has been fully
initialized.

This fixes a crash when two instances of plug are instantiated back to
back and the format conversion plugin inserted by the second is skipped
by the first because the fast_ops pointer is not properly updated.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/src/pcm/pcm_plug.c b/src/pcm/pcm_plug.c
index e9d2923..72456d5 100644 (file)
--- a/src/pcm/pcm_plug.c
+++ b/src/pcm/pcm_plug.c
@@ -659,8 +659,6 @@ static int snd_pcm_plug_insert_plugins(snd_pcm_t *pcm,
                }
                if (err) {
                        plug->gen.slave = new;
-                       pcm->fast_ops = new->fast_ops;
-                       pcm->fast_op_arg = new->fast_op_arg;
                }
                k++;
        }
@@ -1049,6 +1047,9 @@ static int snd_pcm_plug_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
        }
        snd_pcm_unlink_hw_ptr(pcm, plug->req_slave);
        snd_pcm_unlink_appl_ptr(pcm, plug->req_slave);
+
+       pcm->fast_ops = slave->fast_ops;
+       pcm->fast_op_arg = slave->fast_op_arg;
        snd_pcm_link_hw_ptr(pcm, slave);
        snd_pcm_link_appl_ptr(pcm, slave);
        return 0;