[issue1158] Problems with a SATA DVD burner

[Steve O'Hara-Smith]

	Hi,

	I'm not so sure about this - I just tried your 19 Nov version (I
didn't notice the commit earlier sorry), it gives me an interrupt storm on
boot while the 17 Nov version (DMA only on read/write) does not - but will
only burn once.

	There was an issue with non aligned DMA transfers that Matt fixed
(with changes to physio() around on 10 August). From the commit message it
allocates a bounce buffer if the buffer is not 16 byte aligned - I don't
understand the code well enough to see how the bounce buffer is aligned but
presumably it is at least 16 byte.

On Mon, 1 Dec 2008 15:16:05 +0200
Hasso Tepper <hasso at estpak.ee> wrote:

> To clarify the state of the bug ...
> 
> The issue with SATA CD/DVD devices causing interrupt storms etc are
> solved in both master and 2.0 branch. There are still issue with
> recording though:
> 
> acd0: FAILURE - READ_BUFFER ILLEGAL REQUEST asc=0x24 ascq=0x00
> acd0: FAILURE - READ_BUFFER ILLEGAL 
> ata4: FAILURE - non aligned DMA transfer 
> acd0: setting up DMA failed
> 
> I think that it's not specific to SATA CD/DVD writers though. And I 
> thought Matt already fixed the issues with non aligned DMA transfers? Or 
> was it in different path?
> 
> I don't have time and knowledge to work on this, but I think that it's 
> showstopper for 2.2. Any takers?
> 
> 


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