On Wednesday 11 September 2002 20.48, you wrote: > On Wed, 11 Sep 2002, Anders Torger wrote: > > I use a RME9652 hammerfall with two periods (the hardware is that > > way). > > > > I watch a file descriptor associated to the output with select(), > > when it gets ready for writing, I write data to the pcm with > > snd_pcm_writen(). In the beginning, the state of the pcm is > > PREPARED. > > > > What I would expect then, is that the file descriptor is ready for > > writing until the two periods has been filled with data, and then > > select will block (output buffers full, sound card not running). > > But instead, when the two periods is filled with data, select() > > still returns and says that the file descriptor is ready for > > writing, but when calling snd_pcm_writen(), it returns -EPIPE. The > > pcm state is still PREPARED. > > > > What is wrong? Is it me (probably), or is it alsa? > > You should also check for POLLERR. I'm not sure, that it's necessary > to return POLLOUT together with POLLERR in that case. Anyway, > application should check for POLLERR at first and then write data.
I'm sorry, I don't understand, what would be the error in the above case? I just want to watch the file descriptor for writing, and expect that it will be triggered when there is available space in the output buffer to write to, or, if there is an error, for example broken pipe. But how could it be broken pipe if the pcm is in state PREPARED? It has never been put into RUNNING. The problem here is that the output buffer is full, the pcm is not RUNNING, but the file descriptor gets triggered anyway. When can that happen? /Anders Torger ------------------------------------------------------- In remembrance www.osdn.com/911/ _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
