Messages in this thread | | | Date | Fri, 29 Jun 2001 20:09:42 +0200 | From | (Gunther Mayer) | Subject | Re: Patch(2.4.5): Fix PCMCIA ATA/IDE freeze (w/ PCI add-in cards)V3 |
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Andre Hedrick wrote: > > That is a legacy bit from ATA-2 but it is one of those things you can not > get rid of :-( even thou things are obsoleted, they are not retired. > This means that you have to go back into the past to see how it was used, > silly! I hope you agree to that point.
No, 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 ?
> > This is the drive->ctrl register pointer. > > outp(drive->ctl|0x02, IDE_CONTROL_REG); > > typedef union { > unsigned all : 8; /* all of the bits together */ > 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 */ > } b; > } control_t; > > This is a new struct that is to be added for 48-bit addressing and it will > reflect drive->ctl soon. I have not decided how to use it best or at all, > but it has meaning and once I add-in the real def of bit3 then I will not > need to look it up again. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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