Patch(2.4.5): Fix PCMCIA ATA/IDE freeze (w/ PCI add-in cards)V3

Andre Hedrick wrote:

> That is a legacy bit from ATA-2 but it is one of those things you cannot > get rid of :-(

in ANSI X3.279-1996, "AT Attachment Interface with Extensions (ATA-2)", Approved September 11, 1996 , control register bit 3-7 are reserved.

However ANSI X3.221-1994, "AT Attachment Interface for Disk Drives", Approved May 12, 1994, bit3 is "1" and bits 4-7 are "x". No further explanation.

How far back must we go, to get the sense ?

> struct {
> unsigned bit0 : 1;
> unsigned nIEN : 1; /* device INTRQ to host */
> unsigned SRST : 1; /* host soft reset bit */
> unsigned bit3 : 1; /* ATA-2 thingy */
> unsigned reserved456 : 3;
> unsigned HOB : 1; /* 48-bit address ordering */
> } control_t;
>
> once I add-in the real def of bit3 then I will not > need to look it up again.

bit3: 0: drive has 1-8 heads
1: drive has more than 8 heads

(From old MFM/RLL times. In ATA-1 bit3 is set to 1. See also

	http://www.win.tue.nl/~aeb/linux/hdtypes/hdtypes-2.html

.)

Andries

I should have known that you (instructor of the current and previous maintainer) would have the answer off the top ;-)
Therefore by your description it mys be set always but I guess it is a DGD; however, I do want to know that it is now.

Oh, and now that Big Drive Technology has been annouced I should finally send you the code for 48-bit, sorry about the delay.

Cheers,

Andre Hedrick
ASL Kernel Development
Linux ATA Development
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