tree e68cfe5e88d155d1a6820b563517dac27b8e6dd6
parent 64f1607ffbbc772685733ea63e6f7f4183df1b16
author Takashi Iwai <tiwai@suse.de> 1250779216 +0200
committer Takashi Iwai <tiwai@suse.de> 1250779216 +0200

ALSA: pcm - Fix drain behavior in non-blocking mode

The current PCM core has the following problems regarding PCM draining
in non-blocking mode:

- the current f_flags isn't checked in snd_pcm_drain(), thus changing
  the mode dynamically via snd_pcm_nonblock() after open doesn't work.
- calling drain in non-blocking mode just return -EAGAIN error, but
  doesn't provide any way to sync with draining.

This patch fixes these issues.
- check file->f_flags in snd_pcm_drain() properly
- when O_NONBLOCK is set, PCM core sets the stream(s) to DRAIN state
  but quits ioctl immediately without waiting the whole drain; the
  caller can sync the drain manually via poll()

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