[alsa-devel] [PATCH 0/5] Echoaudio - add suspend/resume support

Giuliano Pochini pochini at shiny.it
Sat Jan 30 16:31:23 CET 2010

The following patch set adds suspend/resume support to all echoaudio drivers.
It has been tested on an IndigoIOx and a Gina3G. Rawmidi device has been
tested partially. PCM and controls interfaces have been tested more and I
think it's reasonably safe. I also have a Gina24 and a Gina3G, but I didn't
test suspend/resume with them because I couldn't manage to make PM test
system work on my pmac.

Echoaudio soundcards do not support power management and Dx PCI states.
Anyway, the card can enter a "comatose" state by sending a command to the
DSP that is supposed to turn parts of the hardware off and reduce power
consumption. Doing that causes the loss of the card's internal state, thus
it is impossible, upon resume, to make the card continue from the exact
point where it was suspended. The driver restores all controls and PCM
settings and the applications have to call prepare() to restart the
substreams. Rawmidi is restarted automatically, but some data in the i/o
buffers may be lost.


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