linux-ide.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* ata_pio_need_iordy vs. CF spec. V4.1
@ 2008-11-24 17:40 David Daney
  2008-11-24 17:45 ` Alan Cox
  0 siblings, 1 reply; 3+ messages in thread
From: David Daney @ 2008-11-24 17:40 UTC (permalink / raw)
  To: IDE/ATA development list

Table 22 on page 51 of CF Specification Rev. 4.1 indicates that iordy is 
not supported in PIO5 and PIO6.  This seems to be in conflict with the 
code in ata_pio_need_iordy, which asserts that it is mandatory in any 
mode greater than PIO2.

Which is correct?  Or am I misreading something?


Thanks,
David Daney

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: ata_pio_need_iordy vs. CF spec. V4.1
  2008-11-24 17:40 ata_pio_need_iordy vs. CF spec. V4.1 David Daney
@ 2008-11-24 17:45 ` Alan Cox
  2008-11-24 19:02   ` Sergei Shtylyov
  0 siblings, 1 reply; 3+ messages in thread
From: Alan Cox @ 2008-11-24 17:45 UTC (permalink / raw)
  To: David Daney; +Cc: IDE/ATA development list

On Mon, 24 Nov 2008 09:40:10 -0800
David Daney <ddaney@caviumnetworks.com> wrote:

> Table 22 on page 51 of CF Specification Rev. 4.1 indicates that iordy is 
> not supported in PIO5 and PIO6.  This seems to be in conflict with the 
> code in ata_pio_need_iordy, which asserts that it is mandatory in any 
> mode greater than PIO2.
> 
> Which is correct?  Or am I misreading something?

The ATA spec says that modes > PIO2 requires IORDY

The CFI spec does indeed say PIO5/6 do not use IORDY so probably you
should tweak that function at least for CFA devices.

Alan


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: ata_pio_need_iordy vs. CF spec. V4.1
  2008-11-24 17:45 ` Alan Cox
@ 2008-11-24 19:02   ` Sergei Shtylyov
  0 siblings, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2008-11-24 19:02 UTC (permalink / raw)
  To: Alan Cox; +Cc: David Daney, IDE/ATA development list

Alan Cox wrote:

>>Table 22 on page 51 of CF Specification Rev. 4.1 indicates that iordy is 
>>not supported in PIO5 and PIO6.  This seems to be in conflict with the 
>>code in ata_pio_need_iordy, which asserts that it is mandatory in any 
>>mode greater than PIO2.

>>Which is correct?  Or am I misreading something?

> The ATA spec says that modes > PIO2 requires IORDY

> The CFI spec does indeed say PIO5/6 do not use IORDY so probably you
> should tweak that function at least for CFA devices.

    Only for them because there probably used to be PIO5 hard disks in the 
wild and they hardly ignored IORDY...

> Alan

MBR, Sergei

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2008-11-24 19:02 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-11-24 17:40 ata_pio_need_iordy vs. CF spec. V4.1 David Daney
2008-11-24 17:45 ` Alan Cox
2008-11-24 19:02   ` Sergei Shtylyov

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).