I can't see any reason, why my i845 updates should touch dma stuff... 

The only changes I could think of causing troubles are 
1. dma reset (line 790, 842): no check if dma reset is complete
2. dma reset: reset occurs before latent interrupt bits are cleared
3. channel support (lines 1951 ff): more bits are cleared then should
   be? (look for 0xcfffff, shouldn't that read 0xffcfffff; compare
   lines 2829 and 2487)
4. At least on ICH4, OFF_CIV is a read only location, but writes
   occur quite frequently.

Don't know if that helps.

George

P.S.: The attached patch goes to Alan seperately. Give it a try. (You
can also remove the comment tags from line 795:
	while( inb(card->iobase + PI_CR) & 0x02 ) ;
and line 849
	while( inb(card->iobase + PO_CR) & 0x02 ) ;
They are  not necessary on my box, but...
)
	
On Tue, 2002-08-27 at 20:46, Doug Ledford wrote:
> On Tue, Aug 27, 2002 at 12:53:12PM +0300, Andris Pavenis wrote:
> > Found that i810_audio has been broken in kernel 2.4.20-pre4-ac1. It was Ok with 
> > 2.4.20-pre1-ac1 I used before.
> > 
> > With 2.4.20-pre4-ac1 I'm only getting garbled sound and kernel messages (see below).
> > Didn't have time yet to study mire detailed which change breaks driver.
> 
> The important part of my change is just two lines.  There is the line that 
> prints out the message "Defaulting to base 2 channel mode." and the line 
> after it where we mask off a couple bits in the global control register.  
> Comment those two lines out and let me know if it makes a difference on 
> your machine.
> 
> > In Alan's changelog I see:
> > 
> > 2.4.20-pre2-ac5: Further i810_audio updates for 845 (Juergen Sawinski) 
> > 2.4.20-pre1-ac3: Tidy up error paths on i810_audio init (Alan) 
> > 2.4.20-pre1-ac2: First set of i810 audio updates (Doug Ledford) 
> > 
> > Andris
> > 
> > ------ at startup -----------------
> > Intel 810 + AC97 Audio, version 0.22, 11:18:00 Aug 26 2002
> > PCI: Found IRQ 5 for device 00:1f.5
> > PCI: Sharing IRQ 5 with 00:1f.3
> > PCI: Setting latency timer of device 00:1f.5 to 64
> > i810: Intel ICH 82801AA found at IO 0xe100 and 0xe000, MEM 0x0000 and 0x0000, IRQ 5
> > i810_audio: Audio Controller supports 2 channels.
> > i810_audio: Defaulting to base 2 channel mode.
> > i810_audio: resetting hw channel 0
> > ac97_codec: AC97 Audio codec, id: 0x4144:0x5348 (Analog Devices AD1881A)
> > i810_audio: AC'97 codec 0 Unable to map surround DAC's (or DAC's not present), to
> > ------ error messages  ------------
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 27, hwptr 253a, count -13626
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 27, hwptr 2662, count -296
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 27, hwptr 2662, count -296
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 27, hwptr 266a, count -8
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 1, LVI 31, hwptr 2924, count -10526
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 1, LVI 31, hwptr 2924, count -10526
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 3, hwptr 253a, count -5434
> > i810_audio: DMA overrun on write
> > i810_audio: CIV 0, LVI 3, hwptr 2562, count -40
> > ......
> > 
> > ---------  error message from artsd (KDE-3.1 beta1) -------
> > Sound server fatal error:
> > AudioSubSystem::handleIO: write failed
> > len = 3228, can_write = 4096, errno = 17 (File exists)
> > This might be a sound hardware/driver specific problem (see aRts FAQ)
> > 
> > -------------------------------------------------------------------- 
> > Kernel was compiled with gcc-3.1 (like earlier kernels where i810_audio worked
> > Ok)
> 
> -- 
>   Doug Ledford <dledford@redhat.com>     919-754-3700 x44233
>          Red Hat, Inc. 
>          1801 Varsity Dr.
>          Raleigh, NC 27606
>   
> -
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-- 
Juergen "George" Sawinski
Max-Planck Institute for Medical Research
Dept. of Biomedical Optics
Jahnstr. 29
D-69120 Heidelberg
Germany

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