Re: [PATCH] ide: don't set PIO mode on pre-EIDE drives

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Alan Cox wrote:

>>>>Fix handling of  the PIO modes for the pre-EIDE drives that did not support
>>>>the PIO Flow Control Transfer Mode value (00001 nnn) of the Set Transfer Mode
>>>>feature by  skipping the actual mode programming.

>>>You also need to cater for CF 1.1 compliant devices which do not have set
>>>xfer mode.

>>    Do they have IORDY support?

> Good question. 

    I thought you know. :-)

> CF 1.4 says set features supports 01/0A/55/66/81/8A/9A/BB/CC
> (with 69/96/97 NOP or not recommended)

    Well, the same spec says IORDY may be supported and bit 11 of word 49 may 
be set.  Obviously, no PIO3/4 though.

> However it documents both the PIO mode and DMA word in identify. I've

    So what? That's PIO2 at max, and *default* mode at that, not changeable.

> never seen a CF 1.x card which does DMA or PIO > 2.

    That's something at least.  I hope they also don't set bit 11 -- 
otherwise, bad luck.  Or am I supposed to also check the CF signature? :-)

> CF 1.x is sort of ATA-2 ish but without some set features (eg its got
> idle immediate) and with some stuff that became general later (security
> features)

    Well, at least CF 2.1 documents every imaginable feature value, it seems, 
including Set Transfer Mode of all flavors.

> Alan

MBR, Sergei