Re: [2.6 patch] schedule obsolete OSS drivers for removal

Takashi Iwai
2006-01-04T17:54:48Z

At Wed, 4 Jan 2006 11:37:26 +0100,
tapas wrote:
>
> -- ALSA's default open mode is "blocking". But the ALSA API uses the
> term blocking in two meanings and throws them together into the open
> mode of a pcm device. Normally on device files, blocking access means a
> read()/write() returns, when there's data which has actually been
> read/written to the device. nonblocking access means, read()/write()
> return immediately. In ALSA blocking mode means above _plus_ that the
> open call will only immediately return (in case of contention) when the
> previous user of the audio device has given it up.
>
> The combination of the last two is deadly :) It leaves users with
> nonfunctional sound plus seemingly hanging apps when their soundcard is
> not hardware mixing capable. So IMHO, to fix these two issues really is
> the most pressing matter of all, but like i said, sadly ALSA devs seem
> to disagree (i haven't followed ALSA development that closely lately
> though).

Note that as of OSS emulation, this is no longer true. The OSS
devices are opened as "non-blocking" per default. ALSA native devices
are opened as "blocking" just to keep the compatible behavior,
though.

Takashi