Re: [PATCH] libata: Add a drivers/ide style DMA disable

[Jeff Garzik <jeff@garzik.org>]

Alan Cox wrote:
> This is useful when debugging, handling problem systems, or for
> distributions just to get the system installed so it can be sorted
> out later.
> 
> This is a bit smarter than the old IDE one and lets you do
> 
> libata.pata_dma=0		Disable all PATA DMA like old IDE
> libata.pata_dma=1		Disk DMA only
> libata.pata_dma=2		ATAPI DMA only
> libata.pata_dma=4		CF DMA only
> 
> (or combinations thereof - 0,1,3 being the useful ones I suspect)
> 
> (I've split CF as it seems to be a seperate case of pain and suffering
> different to the others and caused by assorted PIO wired adapters etc)
> 
> SATA is not affected - for one its not clear it makes sense to disable
> DMA for SATA if even always possible, for two we've seen no failure 
> evidence to justify needing to support this kind of hammer on SATA.
> 
> Signed-off-by: Alan Cox <alan@redhat.com>

applied, after making it work on SATA too