[issue1158] Problems with a SATA DVD burner

Tue Dec 16 14:48:48 PST 2008

Hasso Tepper wrote:
There is no solution yet, but I think that I already understand what's 
going on. The problem is that the fix I committed int atapi-cam doesn't 
have any effect in case of SATA controller in AHCI (or RAID) mode, so 
switching IDE controller into IDE or legacy mode might help.

I still have two questions ...

* How non aligned DMA transfer reaches this level at all. Should higher 
  layers try to avoid this?
* Where and how requests should be padded to be aligned to 4 bytes (it's 
  required for SATA ATAPI only?)?
It is an interesting question on where to put this alignment requirement. 
 Sephe argued that our busdma functions already provide an alignment 
tool, so maybe it is just being handled not well enough.  Apart from that, 
I think the ATA driver should take care of that and not the kernel.

cheers
  simon
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