[alsa-devel] AD1988B: ALSA doesn't use dmix automatically
ALSA 1.0.15
http://alsa.opensrc.org/index.php/Dmix
NOTE: For ALSA 1.0.9rc2 and higher you don't need to setup dmix. Dmix is enabled as default for soundcards which don't support hw mixing.
So why if I try to play 2 sounds at the same time, the second one complains the "resource is busy"? Shouldn't it detect that AD1988B can't do hardware mixing and use dmix automatically?
Obs.: I don't have any ~/.asoundrc or /etc/asound.conf lying around.
Thanks!
At Sat, 15 Mar 2008 23:48:52 -0300, Dâniel Fraga wrote:
ALSA 1.0.15
http://alsa.opensrc.org/index.php/Dmix
NOTE: For ALSA 1.0.9rc2 and higher you don't need to setup dmix. Dmix is enabled as default for soundcards which don't support hw mixing.
So why if I try to play 2 sounds at the same time, the second one complains the "resource is busy"? Shouldn't it detect that AD1988B can't do hardware mixing and use dmix automatically?
It does as long as the app uses the "default" PCM. The dmix isn't forced to be applied. The exclusive hardware access is still available by opening the PCM as "hw", "plughw" and etc. So, if any apps access exclusively, others will suffer.
Takashi
On Mon, Mar 17, 2008 at 8:45 AM, Takashi Iwai tiwai@suse.de wrote:
At Sat, 15 Mar 2008 23:48:52 -0300,
Dâniel Fraga wrote:
ALSA 1.0.15
http://alsa.opensrc.org/index.php/Dmix
NOTE: For ALSA 1.0.9rc2 and higher you don't need to setup dmix. Dmix is enabled as default for soundcards which don't support hw mixing.
So why if I try to play 2 sounds at the same time, the secondone complains the "resource is busy"? Shouldn't it detect that AD1988B can't do hardware mixing and use dmix automatically?
It does as long as the app uses the "default" PCM. The dmix isn't forced to be applied. The exclusive hardware access is still available by opening the PCM as "hw", "plughw" and etc. So, if any apps access exclusively, others will suffer.
Applications normally offer the real devices as first choices and not the "default" PCM. Perhaps this should be explained better in the documentation or the wiki, not only for the end users, but also for application developers.
At Mon, 17 Mar 2008 20:18:35 +0500, Alexander E. Patrakov wrote:
Takashi Iwai wrote:
It does as long as the app uses the "default" PCM
...and a card-specific file exists under /usr/share/alsa/cards. This is not the case, e.g., for sb16 (just try it in qemu and compare with ens1370--qemu can emulate both of them).
Well, it's basically a bug -- the config remains so because it wasn't confirmed to work. If it's OK on your system, let us know. We'll change the configuration.
Takashi
participants (4)
-
A. C. Censi -
Alexander E. Patrakov -
Dâniel Fraga -
Takashi Iwai