non aligned DMA transfer attempted

[Mel Flynn]

On Thursday 03 September 2009 23:21:10 Alexander Motin wrote:
> Ryan Rogers wrote:
> > I'm having a bit of a problem getting my DVD drive(s) to work correctly.
> >   I'm trying to transfer my DVD collection to my media server, but
> > whenever I run vobcopy, /var/log/messages gets spammed with:
> >
> > acd0: FAILURE - non aligned DMA transfer attempted
> > acd0: setting up DMA failed
> >
> > I added a bit more information to the first message to see if I could
> > figure out what was actually going on.  request->data was 0xd40e0c37,
> > ch->dma.alignment was 2, and request->bytecount was 2048.
>
> Actually I don't understand what for this check was made there. It is
> busdma infrastructure business to implement buffer bouncing to manage
> requested alignment. But this check enforces application level to bother
> with this. Usually it works fine, as memory often allocated aligned. But
> probably here is some specifics in your application. Could you try to
> just to comment-out that request->data check?

+1 on 7.2-STABLE machine, using cam layer. multimedia/handbrake is the 
offending app, that then keeps going into a loop requesting "title one of 8". 
If suspended, the app is not killable and reboot does not shut down the 
machine. Hard power off is needed.
Preceding the spam is:
kernel: (cd0:ata1:0:0:0): Media region code is mismatched to logical
 unit region

I've been assured there's no media region code mismatch (US DVD with US DVD-
ROM). Just reproduced with mplayer:

$ mplayer -vo null dvd://1
MPlayer 1.0rc2-4.2.1 (C) 2000-2007 MPlayer Team
CPU: AMD Athlon(tm) XP 3000+ (Family: 6, Model: 10, Stepping: 0)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 0
Compiled with runtime CPU detection.

Playing dvd://1.
There are 8 titles on this DVD.
There are 31 chapters in this DVD title.
There are 1 angles in this DVD title.
audio stream: 0 format: ac3 (5.1) language: en aid: 128.
audio stream: 1 format: ac3 (5.1) language: fr aid: 129.
audio stream: 2 format: ac3 (5.1) language: es aid: 130.
number of audio channels on disk: 3.
subtitle ( sid ): 0 language: en
subtitle ( sid ): 1 language: fr
subtitle ( sid ): 2 language: es
subtitle ( sid ): 3 language: en
subtitle ( sid ): 4 language: fr
subtitle ( sid ): 5 language: es
number of subtitles on disk: 6

kernel: unknown: FAILURE - REPORT_KEY ILLEGAL REQUEST asc=0x6f ascq=0x04
kernel: (cd0:ata1:0:0:0): REPORT KEY. CDB: a4 0 0 0 12 ac 0 0 0 c 4 0
kernel: (cd0:ata1:0:0:0): CAM Status: SCSI Status Error
kernel: (cd0:ata1:0:0:0): SCSI Status: Check Condition
kernel: (cd0:ata1:0:0:0): ILLEGAL REQUEST asc:6f,4
kernel: (cd0:ata1:0:0:0): Media region code is mismatched to logical unit 
region
kernel: (cd0:ata1:0:0:0): Retrying Command (per Sense Data)
kernel: unknown: FAILURE - REPORT_KEY ILLEGAL REQUEST asc=0x6f ascq=0x04
kernel: (cd0:ata1:0:0:0): REPORT KEY. CDB: a4 0 0 0 12 ac 0 0 0 c 4 0
kernel: (cd0:ata1:0:0:0): CAM Status: SCSI Status Error
kernel: (cd0:ata1:0:0:0): SCSI Status: Check Condition
kernel: (cd0:ata1:0:0:0): ILLEGAL REQUEST asc:6f,4
kernel: (cd0:ata1:0:0:0): Media region code is mismatched to logical unit 
region
kernel: (cd0:ata1:0:0:0): Retries Exhausted
kernel: ata1: FAILURE - non aligned DMA transfer attempted
kernel: unknown: setting up DMA failed

The above system is a desktop with:
<HL-DT-ST DVD-ROM GDR8162B 0019>   at scbus3 target 0 lun 0 (probe0,pass4,cd0)

If needed, I can upgrade this system to stable/8, rather not upgrade it to 
head.
-- 
Mel