Hello. Eric D. Mudama wrote:
> Bit #4, when actually implemented, is a rotational seek indicator, > which can be used for timing purposes.
Hm, I thought it was DSC (drive seek complete) set by the SEEK command completion, and it's always implemented. Didn't you mean IDX (bit 1, IIRC)?
0x50 is the standard, non queueing "device is ready" status. It used to have those special meanings, but they're pretty obsolete today as I understand it.
Erm, some status bits maybe obsolete but I've never heard that the status *values* were specified to mean anything special anywhere...
0x40 is used for queueing, because bit 4 was the service bit for PATA TCQ.
I know. This meaning (SERVICE) actualy came from ATAPI
> But when BUSY (bit #7) is set, the rest are generally nonsense.
Indeed...
WBR, Sergei
Typically, 0x80 as the busy state indicates the device is in POR reset. Once the firmware is up and running in the device, it often switches from 0x80 to 0xD0 during POR.
Oh, I guess it's completely up to the disk makers what other status to show with BSY=1.
0xD0 is the busy state you'd get to if you were 0x50 and received a command, so this is reported typically after the device is up and running.
0x7F usually is hardware indicating nothing is attached to the port, and isn't supposed to infer a non-busy state.
Ha, *never* seen that one. It's has always been 0xFF since PC people didn't ever bother themselves with silly pulldowns. :-)
You're right, while not meaningful according to spec, you can derive some information from the reported status even when you're only supposed to look at one bit.
Well, to some extent... WBR, Sergei - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
