ATA streaming feature support

ATA streaming feature support

[Manish Regmi]

Hi all,
   First of all sorry for bringing this topic again.
As discussed in  --> http://lkml.org/lkml/2006/5/5/47
The ATA Streaming feature set is not necessary to be in Kernel Space
(IDE driver). There is a suggestion creating user space library.

But how is the user space apps going to use the commands like READ
STREAM DMA EXT (0x2A). Shouldn't there be some support in kernel which
setups up PRD tables  and all.
It doesn't seem to be possible.... is it?

Does it sound normal if we have something like O_STREAM in open() or a
seperate IOCTL to command the driver to use STREAM commands (if
supported).

Will this feature be useful for streaming media apps like DVRs? (i am
working in one such.)


-- 
---------------------------------------------------------------
regards
Manish Regmi

---------------------------------------------------------------
UNIX without a C Compiler is like eating Spaghetti with your mouth
sewn shut. It just doesn't make sense.

Re: ATA streaming feature support

[Jeff Garzik]

Manish Regmi wrote:
> Hi all,
>   First of all sorry for bringing this topic again.
> As discussed in  --> http://lkml.org/lkml/2006/5/5/47
> The ATA Streaming feature set is not necessary to be in Kernel Space
> (IDE driver). There is a suggestion creating user space library.
> 
> But how is the user space apps going to use the commands like READ
> STREAM DMA EXT (0x2A). Shouldn't there be some support in kernel which
> setups up PRD tables  and all.
> It doesn't seem to be possible.... is it?

If you pass SG_IO addresses, they become DMA scatter/gather tables.

	Jeff

Re: ATA streaming feature support

[Manish Regmi]

On 1/7/07, Jeff Garzik <jeff@garzik.org> wrote:
> Manish Regmi wrote:
> > Hi all,
> >   First of all sorry for bringing this topic again.
> > As discussed in  --> http://lkml.org/lkml/2006/5/5/47
> > The ATA Streaming feature set is not necessary to be in Kernel Space
> > (IDE driver). There is a suggestion creating user space library.
> >
> > But how is the user space apps going to use the commands like READ
> > STREAM DMA EXT (0x2A). Shouldn't there be some support in kernel which
> > setups up PRD tables  and all.
> > It doesn't seem to be possible.... is it?
>
> If you pass SG_IO addresses, they become DMA scatter/gather tables.
>
>         Jeff

Thank you for your answer.

But what about PATA disks. Is that ioctl supported in PATA disk?
I tried to give IDENTIFY command but it failed with invalid argument.

Regards
Manish Regmi