Messages in this thread | | | Subject | Re: [regression] 2.6.25-rc4 snd-es18xx broken on Alpha | Date | Sun, 9 Mar 2008 18:57:59 -0500 (CDT) | From | (Bob Tracy) |
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Ivan Kokshaysky wrote: > Sounds like a DMA screwup.
Agreed. There's a comment line near the top of the es18xx.c that has been there for a *long* time:
Support for 16 bit DMA seems to be broken. I've no hardware to tune it.
Supposedly with the ES1888, dma1 is for capture, dma2 is for playback. dma2 == 5 is a 16-bit channel, yes? That could explain much...
As for the values "chosen" for dma1 and dma2, they are the ones that keep showing up in the Alpha sound "howto" postings/documents. The driver can cope with dma1 == dma2 by enforcing half-duplex mode in software, but the OSS "sb" driver works fine with the indicated DMA channel values. Besides, if the ES1888 is really capable of full-duplex operation, a potential half-duplex workaround doesn't have much appeal.
> I wonder if it still works on x86 - perhaps you ought to ask ALSA folks.
I tried contacting the driver authors as indicated in the driver source file. Christian Fischbach seems to have disappeared. Still waiting to hear from Abramo Bagnara.
-- ------------------------------------------------------------------------ Bob Tracy | "I was a beta tester for dirt. They never did rct@frus.com | get all the bugs out." - Steve McGrew on /. ------------------------------------------------------------------------
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