I got around my previous problems (readn) in an output/capture application with an envy24 (ice1712) by bypassing the plugin and going straight to hw:0,0. Had to change my code a bit but it's now **almost** working.
I'm now running into underrun problems...occasionally. I am outputting and capturing at 32 bits, 96000 on 4 input channels and 1 output (but of course using hw:0,0 its actually 10 output & 12 input hard-wired). All IO is being stored in RAM buffers and I'm not running into swap. Is my machine simply not fast enough ? (700MHz Pentium, 500M RAM) Help !!! What I don't understand is this: If I put write & read in a loop, with a small 10ms delay, setup both in & out to be non-blocking, I get only occasional underruns. Underruns are unacceptable in my application so I have to completely abort. About every 2nd call to read or write gets an EAGAIN, as you would expect. If, however, I use file descriptor polling before read and write; don't attempt a write till POLLOUT, or a read until POLLIN or POLLPRI, but have the whole lot in a big loop so I handle either as soon as they require, I get failures EVERY time I run. Somewhere about the 5th hardware buffer iteration. Underrun is randomly on read or write. Doing the code "properly" seems to be far worse ! I never get EAGAIN from read/write in this case, and I haven't seen a poll failure yet. Output frame buffer size is 6553, and input 5461, as returned by the hardware. As far as I can see I'm roughly complying with the example code /test/pcm.c with transfer method "write and wait for room in buffer using poll" -- Cheers, Bruce ------------------------------------------------------------------- This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. /\\\/\\\/\\\ / / Bruce Paterson / \\\ \\\ \\\ / / Senior Design Engineer / /\\\/\\\/\\\/ / 87 Peters Ave, Mulgrave, Vic, 3170 / / \\\ \\\ \\\ / PO Box 4112, Mulgrave, Vic, 3170, Australia / / \\\/\\\ \\\/ Ph: +61 3 8561 4232 Fax: +61 3 9560 9055 Tele-IP Ltd. Email: [EMAIL PROTECTED] Icq: #32015991 WWW: http://www.tele-ip.com VK3TJN ------------------------------------------------------------------- ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek PC Mods, Computing goodies, cases & more http://thinkgeek.com/sf _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel