Re: DMA problem with kernel >2.6.10

[Bart Samwel <bart@samwel.tk>]

andrea gelmini wrote:
> 	Hardware: Toshiba Satellite P20 (P4-3200 MHz, 512MB RAM) [1]
> 	Software: Debian Unstable
> 	GCC: 3.4.5 [2]
> 	Memtest86+: v.1.60 (stress tools, CPU/RAM and so on, are all happy)
> 	Problem: with kernel <=2.6.10 everything is all right...
> 	but with any kernel released after 2.6.10 (pre, rc, stable, mm, and
> 	so on), I've got this:
> 
> hda: dma_timer_expiry: dma status == 0x21
> hda: DMA timeout error
> hda: dma timeout error: status=0xd0 { Busy }
[...]
> 	It happen quickly if I do also something like this:
> 	
> 	cd /proc/sys/vm
> 	echo 100 > dirty_background_ratio
> 	echo 1000000 > dirty_expire_centisecs
> 	echo 100 > dirty_ratio
> 	echo 1000000 > dirty_writeback_centisecs

I've had a report about this before, from someone who was using laptop 
mode -- same error message. Funny thing is, the laptop mode tools 
scripts also modify the above values, so it's probably the same problem. 
Until now I thought it was a Thinkpad hardware problem, because I only 
heard about these problems on Thinkpads, but apparently it's a kernel 
problem after all. Don't know anything about the causes though.

--Bart