libata extension

libata extension

[Vitaliyi]

Good Day

Say i want to implement extended set of ATA commands available to
userspace for building diagnostic tools.
I need 0x40 -- read verify and 0x32 -- write long with error handling,
for example. I was trying ide driver through ioctl's, but seems it
lack of functionality and full of gotchas. Furthermore it oopses
sometimes.

Is it possible to use libata for such purpose or i need to write
separate IDE driver ?
By the way, i'm sure it should be done in kernel space since i'm going
to deal with some hdd manufacturer commands.

P.S. I was looking through libata and ide sources and documentation
but still dont have broad picture.


Thanks

Re: libata extension

[Robert Hancock]

Vitaliyi wrote:
> Good Day
> 
> Say i want to implement extended set of ATA commands available to
> userspace for building diagnostic tools.
> I need 0x40 -- read verify and 0x32 -- write long with error handling,
> for example. I was trying ide driver through ioctl's, but seems it
> lack of functionality and full of gotchas. Furthermore it oopses
> sometimes.
> 
> Is it possible to use libata for such purpose or i need to write
> separate IDE driver ?
> By the way, i'm sure it should be done in kernel space since i'm going
> to deal with some hdd manufacturer commands.
> 
> P.S. I was looking through libata and ide sources and documentation
> but still dont have broad picture.

I believe you should be able to do this by sending ATA pass-through SCSI 
commands into the device using SG_IO, without any kernel changes. It's 
really the mechanism that's meant for this..

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

Re: libata extension

[Alan Cox]

> I believe you should be able to do this by sending ATA pass-through SCSI 
> commands into the device using SG_IO, without any kernel changes. It's 
> really the mechanism that's meant for this..

It should work, but Mark Lord reported some problems with READ_LONG on
PIIX/ICH intel chipsets. I don't know if he ever resolved them but if not
I have a patch that ought to.

Alan

Re: libata extension

[Bartlomiej Zolnierkiewicz]

Hi,

On Sunday 11 March 2007, Vitaliyi wrote:
> Good Day
> 
> Say i want to implement extended set of ATA commands available to
> userspace for building diagnostic tools.
> I need 0x40 -- read verify and 0x32 -- write long with error handling,

Mark Lord is working on READ/WRITE_LONG support for libata,
he has posted draft patch recently on linux-ide mailing list.

[ Please consider reading/joining linux-ide@vger.kernel.org ML,
  it is where Linux ATA discussion happens... ]

> for example. I was trying ide driver through ioctl's, but seems it
> lack of functionality and full of gotchas. Furthermore it oopses
> sometimes.

READ/WRITE_LONG is unsupported and as you've already noticed
TASKFILE ioctls are full of gotchas...

> Is it possible to use libata for such purpose or i need to write
> separate IDE driver ?

It should be possible using ATA pass-through, some libata changes
may be required but it is the right way to go IMO.

Bart

Re: libata extension

[Mark Lord]

Vitaliyi wrote:
> Good Day
> 
> Say i want to implement extended set of ATA commands available to
> userspace for building diagnostic tools.
> I need 0x40 -- read verify and 0x32 -- write long with error handling,
> for example. I was trying ide driver through ioctl's, but seems it
> lack of functionality and full of gotchas. Furthermore it oopses
> sometimes.

Use the SCSI SG_IO ioctl() with opcode=ATA_16,
which gives you access to the ATA Passthrough mechanism.
This will work for most ATA commands.

I already use it in hdparm and in some other utilities
for scanning/repairing drives.

A notable exeception are the READ/WRITE LONG opcodes,
which require an extra kernel patch from me,
awaiting merge into libata some year.

Cheers

-ml