Re: [regression] 2.6.25-rc4 snd-es18xx broken on Alpha

From: Rene Herman
Date: Mon Mar 10 2008 - 11:17:18 EST


On 10-03-08 08:34, Michael Cree wrote:

Bob Tracy wrote:

Supposedly with the ES1888, dma1 is for capture, dma2 is for playback. dma2 == 5 is a 16-bit channel, yes? That could explain much...

It is, but what would it explain? You're only having playback problems, right?


As for the values "chosen" for dma1 and dma2, they are the ones that
keep showing up in the Alpha sound "howto" postings/documents.

Running 'show config' in SRM on my Alphas (PWS500au and XP1000) reveals
the settings (except possibly for mpu_port) for the ESS1888 sound chip.
I recall that they are as reported in Alpha sound howtos.

Can it be forced to use dma2=0 (an 8-bit channel, and the usual capture channel on es18xx)? However, that might not be the issue anyway:

I hadn't been using the ESS1888 for awhile, but have just tried it out
since you reported problems. I am running kernel 2.6.24.3 and Debian
testing on the XP1000. I tried playing a number of wav files with
alsa's aplay, sox's play and with mocp. I found that aplay and mocp
worked reliably through the ESS1888. Sox's play on some files did play
back a small extra segment of the file - particularly on short files and
usually some section near the end of the file - once it had completed
playing the file once; maybe this is what you are also observing.

This sounds very suspiciously like a difference with playing through the native ALSA interface and the OSS emulaion. Could you and/or Bob confirm that sox is using the OSS emulation and not ALSA natively?

I could very well imagine the ALSA OSS emulation being broken on Alpha. I doubt any of teh developers has an Alpha. And if aplay works correctly this seems very likely.

"sox" _can_ use ALSA natively as well by the way (see manpage for the version you have installed).

More onerously, my testing eventually ended in a complete system lock up!
I ran play (or was it aplay - sorry can't remember now)

Vital if play is using the OSS interface...

and the system locked up. Got a response with ping across the network but
couldn't log in via ssh. Have been playing mplayer through the ESS1888
for the last couple of days (don't like it though - the sound quality of
the ESS1888 is not good enough for my ears) and haven't had another one
of those lockups since.

Mmm.

Rene.
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